## 1. Features of Criminal Law




The life of the criminal law begins with criminalization. To
criminalize an act-type--call it \(\phi\)ing--is to make it a
crime to commit tokens of that type. Many claim that if it is a crime
to \(\phi\) then \(\phi\)ing is legally wrongful--it is something that,
in the eyes of the law, ought not to be done (Hart 1994, 27; Gardner
2007, 239; Tadros 2016, 91). On this view, we are not invited to
commit crimes--like murder, or driving uninsured--just as
long as we willingly take the prescribed legal consequences. As far as
the law is concerned, criminal conduct is to be avoided. This is so
whether or not we are willing to take the consequences.




It is possible to imagine a world in which the law gets its
way--in which people uniformly refrain from criminal conduct.
Obviously enough this is not the world in which we live. Imagine \(D\) is
about to \(\phi\). If \(\phi\)ing is a crime, reasonable force may
permissibly be used to prevent \(D\) \(\phi\)ing. Police officers and private
persons alike have powers to arrest \(D\), and reasonable force may
permissibly be used to make arrests effective.




These powers and permissions exist *ex ante*--prior, that
is, to the commission of crime. We can add those that exist *ex
post*--once crime has been committed. Imagine now that \(D\)
has \(\phi\)ed. As well as the power to arrest \(D\), the criminal law
confers a set of investigative powers designed to help generate
evidence of \(D\)'s criminality: these include powers to stop
and search, to carry out surveillance, and to detain suspects for
questioning. If sufficient evidence is produced, and it is in the
public interest to do so, \(D\) may be charged with a crime. To
exercise these powers is to impose new duties on \(D\)--\(D\)
must submit to the search, remain in detention, and turn up in court
when required. For \(D\) to do otherwise--absent justification or
excuse--is itself criminal. So reasonable force can permissibly
be used against \(D\) if she refuses to co-operate.




The powers and permissions mentioned so far help \(D\)'s accusers
put together their case against \(D\). By the time cases reach the courts
those accusers are typically state officials (or those to whom the
state has delegated official power). Some legal systems do make space
for private prosecutions. But such prosecutions can be discontinued or
taken over by state officials (and their delegates). Those officials
(and delegates) can also continue proceedings in the face of private
opposition, even when the opposition comes from those wronged by \(D\). In
this way, the state exercises a form of control over criminal
proceedings that is absent from legal proceedings of other kinds
(Marshall and Duff 1998).




It may seem from the above that criminal proceedings are tilted
heavily in favour of the accusing side. But the criminal law also
confers rights on the accused that help protect \(D\) against her
accusers (Ashworth and Zedner 2010, 82). These typically include the
right to be informed of the accusations in question, the right to
confidential access to a lawyer, and the privilege against
self-incrimination. Most important of all, perhaps, is the right to be
tried before an independent court that respects the presumption of
innocence--that requires the prosecution to prove beyond a
reasonable doubt that \(D\) committed the crime.




At least on paper, the procedural protections on offer in criminal
proceedings are more robust than those available to the accused in
legal proceedings of other kinds. This is explained in large part by
the consequences of criminal conviction. If \(D\) is found guilty in a
criminal court, \(D\) gains a criminal record. Depending on the crime,
\(D\) may be disenfranchised, banned from certain professions, refused
entry to other countries, and declined access to insurance, housing,
and education (Hoskins 2014; 2016). This is to say nothing of criminal
sentences themselves. Those sentences are typically punishments: the
object of the exercise is that \(D\) suffer some harm or deprivation;
\(D\) is to be made worse off than she otherwise would have been. This
is not to say that suffering or deprivation must be the ultimate end
of those who punish. That \(D\) suffer or lose out may be a means to
any number of ultimate ends, including deterrence, restoration, or
rehabilitation. What it cannot be is a mere side-effect. This is one
thing that distinguishes criminal sentences--at least of the
punitive kind--from the reparative remedies that are standard
fare in civil law. Those remedies are designed to benefit
\(P\)--to wipe out losses the plaintiff suffered in virtue of the
defendant's wrong. True, \(D\) often loses in the process of
ensuring that \(P\) gains. But we can imagine cases in which this is
not so: in which an award of damages leaves \(D\) no worse off than
\(D\) was before. The award may remain a reparative success. It cannot
be anything other than a punitive failure (Boonin 2008, 12-17;
Gardner 2013).




We can now see that criminalizing \(\phi\)ing does much more than make
\(\phi\)ing a legal wrong. It also makes it the case that \(\phi\)ing
triggers a set of legal rights, duties, powers, and permissions, the
existence of which distinguishes criminal law from the rest of the
legal system. Those rights, duties, powers, and permissions are
constitutive of a criminal process via which suspected \(\phi\)ing
turns into arrest, charge, trial, conviction, and
punishment. Obviously suspicions are sometimes misplaced. Innocent
people's lives are sometimes ruined in consequence. So it is no
surprise that the most destructive powers and permissions are
jealously guarded by the criminal law. Trials held in a
university's moot court might be meticulously fair to
defendants. But a moot court has no power to detain us in advance, to
require us to appear before it, or to sentence us to
imprisonment. Force used to achieve any of these things would itself
be criminal, however proportionate the resulting punishment might
be. As this example shows, criminal law is characterised by an
asymmetry--it bestows powers and permissions on state officials
(and delegates) which are withheld from private persons, such that the
latter are condemned as vigilantes for doing what the former lawfully
do (Thorburn 2011a, 92-93; Edwards forthcoming). This remains the
case--often to the great frustration of victims and their
supporters--even if the official response, assuming it comes at
all, will be woefully inadequate.


## 2. Functions of Criminal Law




Few deny that one function of criminal law is to deliver justified
punishment. Some go further and claim that this is the sole function
of criminal law (Moore 1997, 28-29). Call this *the punitive
view*. Rules of criminal procedure and evidence, on this view,
help facilitate the imposition of justified punishment, while keeping
the risk of unjustified punishment within acceptable bounds. Rules of
substantive criminal law help give potential offenders fair warning
that they may be punished. Both sets of rules combat objections we
might otherwise make to laws that authorize the intentional imposition
of harm. To combat objections, of course, is not itself to make a
positive case for such laws. That case, on the punitive view, is made
by the justified punishments that criminal courts impose. This is not
to say anything about what the justification of
punishment *is*. It is merely to say that criminal law is to be
justified in punitive terms.




Some object that this focus on punishment is misplaced. The central
function criminal law fulfills in responding to crime, some say, is
that of calling suspected offenders to account in criminal courts
(Gardner 2007, 80; Duff 2010c, 16). This view puts the criminal trial
at the centre, not just of criminal proceedings, but of criminal law
as a whole (Duff 2013a, 196). Trials invite defendants to account for
themselves either by denying the accusation that they offended, or by
pleading a defence. The prospect of conviction and punishment puts
defendants under pressure to offer an adequate account. Call this
*the curial view*. It differs from the punitive view in two
ways. First, part of the positive case for criminal law is
*independent* of the imposition of punishment. Second, part of
the positive case for imposing criminal punishment is
*dependent* on the punishment being part of a process of calling
to account. The following two paragraphs expand on both these
claims.




As to the first, we often have reason to account for our actions to
others. We can leave open for now the precise conditions under which
this is so. But it is plausible to think that if Alisha steals from
Bintu she has reason for account for the theft, and that if Chika
intentionally kills Dawn she has reason to account for the killing.
Defenders of the curial view argue that criminal proceedings are of
intrinsic value when defendants (are called to) offer accounts of
themselves that they have reason to offer in criminal courts (Gardner
2007, 190-191; Duff 2010c, 15-17). Imagine Alisha stole
from Bintu because she was under duress. Imagine Chika intentionally
killed Dawn to defend herself or others. Neither of these defendants,
we can assume, is justifiably punished. On the punitive view, criminal
law's function does not stand to be fulfilled. On the curial
view, things are different. Alisha and Chika both have reason to
account for their behaviour--to explain what they did and why
they did it. Criminal proceedings invite each to provide that account
and put each under pressure to do so. Assuming Alisha and Chika have
reason to account in a criminal court, proceedings in which they (are
called to) do so are of intrinsic value. One of criminal law's
functions is fulfilled even if no-one is, or should be, punished.




To endorse the curial view is not, of course, to say that we should do
away with criminal punishment. But it *is* to say that the
connection between trial and punishment is not merely instrumental.
Some think that the facts that make punishment fitting--say,
culpable wrongdoing--obtain independently of criminal proceedings
themselves (Moore 1997, 33). We use those proceedings to ensure that
said facts are highly likely to have obtained--that \(D\) is
highly likely to have culpably committed a wrong. On the curial view,
the fact that \(D\) has been tried and found guilty (or has entered a
guilty plea) is *itself* part of what makes it fitting that
\(D\) is punished. The fitting way to respond to criminal wrongdoing,
on this view, is to call the wrongdoer to account for her wrong. To
call \(D\) to account is to attempt to both (a) get \(D\) to answer
for wrongdoing (as occurs in court), and (b) get \(D\) to confront
wrongdoing for which she has no satisfactory answer (as occurs when
\(D\) is punished). So it is only
*because* \(D\) has first been tried and found guilty (or has
entered a guilty plea) that punishment counts as a fitting response to
\(D\)'s wrong (Gardner 2007, 80; Duff 2013a, 205). We can see
the implications of this view by imagining a world in which trials are
abolished, because some new-fangled machine allows us to identify
culpable wrongdoers with perfect accuracy. Having no doubt that \(D\)
is guilty, we simply impose punishment on \(D\). On the curial view,
the punishments we impose are inherently defective: they are not
imposed as part of a process of calling to account. Though our
new-fangled machine might justify doing away with trials--once we
factor in how expensive they can be--we would lose something of
value in doing away with them.




If criminal law does have a particular function, we can ask whether
that function is *distinctive* of criminal law. We can ask, in
other words, whether it helps distinguish criminal law from the rest
of the legal system. It has been claimed that criminal law is
distinctive in imposing punishment (Moore 1997, 18-30; Husak
2008, 72). One might also claim that criminal law alone calls
defendants to account. But punishments are imposed in civil
proceedings--exemplary damages are the obvious case. And it is
arguable that civil proceedings also call defendants to
account--that they too invite defendants to offer a denial or
plead a defence; that they too use the prospect of legal liability to
put defendants under pressure to account adequately (Duff 2014a).




In response, one might try to refine the function that is distinctive
of criminal law. Perhaps criminal law's function is to respond
to public wrongs (whether by calling to account or punishing such
wrongdoers), whereas the function of civil law is to respond to
private wrongs. What we should make of this proposal depends on what a
public wrong *is* (Lamond 2007; Lee 2015; Edwards and Simester
2017). To make progress, we can distinguish between primary
duties--like duties not to rape or rob--and secondary
duties--like duties to answer, or suffer punishment, for rape or
robbery. We incur duties of the latter kind by breaching duties of the
former.




If the public/private distinction is cashed out in terms of primary
duties, then responding to public wrongs cannot be distinctive of
criminal law. Many wrongs are both crimes and torts. So the two bodies
of law often respond to breaches of the same primary duty. A more
promising proposal looks to secondary duties. Perhaps criminal
law's distinctive function is to respond to wrongs *on behalf
of us all*--to discharge secondary duties owed to the
community as a whole (Duff 2011, 140). Perhaps the function of civil
law is to respond to wrongs *on behalf of some of us*--to
discharge secondary duties owed to particular individuals. This might
be thought to explain why criminal proceedings, unlike civil
proceedings, are controlled by state officials: why officials can
initiate proceedings that individual victims oppose, and discontinue
proceedings that victims initiate.




The view described in the previous paragraph conceives of criminal law
as an instrument of the community--a way of ensuring that the
community gets what it is owed from wrongdoers. Call it *the
communitarian view*. If we combine this with the curial view, the
distinctive function of criminal law is to seek answers owed to the
community as a whole. One might doubt that the functions of criminal
and civil law can be so neatly distinguished. It is arguable that
civil law sometimes responds to wrongs on behalf of all of
us--civil proceedings can be brought against \(D\) on the
basis that her conduct is a nuisance to the public at large, or on the
basis that \(D\) is a public official whose conduct is an abuse of
power. More importantly, one might claim that in the case of
paradigmatic crimes--like robbery, rape, or
battery--criminal law responds to wrongs on behalf of particular
individuals--on behalf of those who have been robbed, raped, or
battered. On this view, a positive case for criminalization need not
await the finding that \(D\) owes something to the whole community. It
is at least sometimes enough that \(D\) owes something to those \(D\)
has wronged, which \(D\) would fail to provide in the absence of
criminal proceedings.




Those who reject the communitarian view might be thought to face the
following difficulty: they might be thought to lack an explanation of
official control over how far criminal proceedings go. If criminal law
seeks what is owed by wrongdoers to the wronged, doesn't
official control amount to theft of a conflict properly controlled by
the two parties (Christie 1977)? Not necessarily. First, we should not
always require the wronged to have to pursue those who have wronged
them. Second, we should not always support those who think themselves
wronged in pursuing alleged wrongdoers. As to the first point, some
are trapped in abusive relationships with those who wrong them. Others
are susceptible to manipulation that serves to silence their
complaints. Some wrongdoers can use wealth and social status to stop
accusers in their tracks. As to the second point, the temptation to
retaliate in the face of wrongdoing is often great. It is all too easy
for the pursuit of justice to become the pursuit of revenge, and for
the perceived urgency of the pursuit to generate false accusations.
Official control can help vulnerable individuals--like those
described above--to get what they are owed. And it can mitigate
the damage done by those trying to exact vengeance and settle scores
(Gardner 2007, 214-216). It can ensure that those in positions
of power cannot wrong others with impunity, and reduce the likelihood
that vindictiveness begets retaliation, which begets violent conflict
from which all lose out (Wellman 2005, 8-10). We can add that
criminal proceedings may help protect others against being wronged in
future. Those wronged may have a duty to give up control of
proceedings in order to provide this protection (Tadros 2011c,
297-299).




These remarks suggest an alternative to the communitarian view.
According to the alternative, the secondary duties of concern in civil
and criminal proceedings are typically one and the same. The positive
case for criminal law's involvement is not that it discharges
duties of interest to the criminal law alone, but that it enables
duties of general interest to be discharged less imperfectly than they
otherwise would be--than they would be if the criminal law took
no interest in them. Call this *the imperfectionist view*. What
is distinctive of criminal law, on this view, is not its function but
its mode of functioning: the manner in which it fulfills functions
shared with other bodies of law.




Some writers seek criminal law's distinctiveness in a different
place. What is distinctive about criminal law, they claim, is that it
publicly censures or condemns. This expressive function is sometimes
associated with criminal punishment (Husak 2008, 92-95).
Because other bodies of law sometimes punish, and because punishment
typically--perhaps necessarily--expresses censure (Feinberg
1970), the expressive function is at least partly shared. But the
message sent by criminal law is not sent only at the sentencing stage.
It is sent the moment a guilty verdict is reached by a criminal
court--by the declaration that \(D\) has been criminally
convicted (Simester 2005, 33-36). The social significance of
conviction is very different to that of (say) the verdict that \(D\)
is a tortfeasor: the former verdict conveys, in and of itself, that
\(D\)'s conduct reflects badly on \(D\). Though additional
detail may generate the same conclusion in the case of a civil
verdict, such detail is not required in the case of criminal
conviction. If this is right, the distinctiveness of criminal law
turns out not to consist in the fact that it provides for
punishment. It turns out to consist (at least in part) in the
provision of a technique for condemning wrongdoers which does not
require that we punish in order to condemn.




So far, we have focused on the functions criminal law fulfills in
response to the commission of crime. It is plausible to think,
however, that criminal law's functions include preventing crime
from occurring. We can see this by asking what success would look like
for the criminal law. Would criminal law have succeeded if all thieves
and murderers were tried and punished? Or would it have succeeded if
there
*was* no theft or murder, because criminalization resulted in
would-be thieves and murderers refraining from such wrongs? Notice that
to pose these two questions as alternatives is not to deny that
*punishment* might be justified in preventive terms. It is
rather to suggest that resorting to punishment to achieve prevention
is already a partial failure for the criminal law. It is a failure to
deter those who, *ex hypothesi*, have already committed
criminal offences. Had the creation of those offences been an
unqualified success, there would have been nothing for which to punish
anyone.




One might hold that criminal law's *sole* function is to
prevent criminal wrongdoing. Call this *the preventive view*.
Defenders of this view need not say that we should enact whatever laws
will achieve the most prevention. That \(X\) is the function of \(Y\)
does not entail that we are justified in doing whatever will achieve
most of \(X\) with \(Y\). That cutting is the function of knives does
not entail that knife-holders are justified in cutting whatever they
see. Holders of the preventive view can, in other words, accept the
existence of constraints on prevention, that are not themselves
justified in preventive terms (Hart 1968, 35-50). What they
cannot accept is a positive case for criminal law that is not
preventive.




Some hold a *mixed view* that combines elements of those
considered above (Alexander and Ferzan 2009, 3-19; Simester and
von Hirsch 2011, 3-18; Tadros 2016, 159-172). One way to
construct such a view is by distinguishing between primary and
secondary functions. Primary functions are those that, when all else
is equal, we have most reason to want the law to fulfil. Secondary
functions are those we have reason to want the law to fulfil if it
fails to fulfil its primary functions. Criminal law's primary
functions, it is plausible to think, are preventive. *Ceteris
paribus*, we have most reason to want criminal law to bring about
a world in which wrongs like theft or murder do not occur. Failing
that, we have reason to want criminal law to call thieves and
murderers to account, and to punish those who have no adequate account
to offer.




There is some scepticism about mixed views. For some, the worries are
conceptual. Moore claims that justified punishment must be imposed for
reasons of desert, and that for this reason the punitive and
preventive functions cannot be combined. We are unable to 'kill two
birds with the proverbial one stone, for by aiming at one of the birds
we will necessarily miss the other' (Moore 1997, 28). Several
replies are available. First, even if this is a problem for a mixed
view of *punishment*, it need not be for a mixed view of
*criminal law*. Grant that punishment must be imposed for
reasons of desert. It does not follow that criminal offences cannot be
created for reasons of prevention. Criminalization and punishment are
different acts, and can be performed for different reasons (Edwards
and Simester 2014). Second, to claim that \(X\) is part of the
positive case for criminal law--that it is one of criminal
law's
*functions*--is not to claim that \(X\) should be part of the
*mission* of every criminal justice official (Gardner 2007,
202). Reasons that help make a positive case for our actions are often
reasons for which we should not act. That one will be financially
secure is a reason to get married, but one should not get married in
order to be financially secure. Similarly, to say that prevention
helps make a positive case for criminal law--and for
punishment--is not to say that judges should punish for that
reason.




Other worries about mixed views are pragmatic (Duff 2010a). As
criminal wrongdoing will persist whatever we do, the preventive
function sets criminal law an insatiable goal. There is a standing
risk that law-makers who pursue that goal will deprive us of a criminal law
that fulfills its other functions. Consider again the curial
view. Plausibly, we have reason to account for wrongs like theft and
fraud in criminal court, but no reason to account for every
interaction with property or all misleading statements from which we
stand to gain. If defendants are to be called to account for the
wrongs, it is these that must be criminalized. To criminalize
trivialities--in pursuit of preventive ends--is to drain
criminal proceedings of their intrinsic value (Duff 2010b). No doubt
these are important worries. But they do nothing to suggest that we
should reject a mixed view. At most, they show that
law-makers *also* should not take prevention to be part of
their mission. As we already saw, this conclusion does not show that
prevention is not part of the positive case for criminal law. And it
may anyway be too strong. Law-makers who exclude prevention from their
mission may refuse to create crimes that would prevent a great deal of
harm. The cost of refusing to create these crimes might be greater
than the cost of calling people to account for trivialities, and this
might be so even when alternative means of prevention are factored
in. If it would, criminal law's preventive function should be
part of the law-making mission: it is a function law-makers should
indeed aim to fulfil.


## 3. Justifications of Criminal Law




In light of the resources it consumes, and the damage it does to
people's lives, it is far from clear that we are justified in
having criminal law. If we should not be abolitionists, criminal law
must be capable of realizing some value that gives us sufficient
reason to retain it. To offer an account of this value is to offer a
*general justification* of criminal law. Obviously enough, the
functions of criminal law tell us something about what this might be.
If the punitive view is correct, criminal law's value consists in
delivering justified punishment. If the curial view is correct, that
value consists (in part) in people offering answers that they have
reason to offer. If the preventive view is correct, it consists in
preventing criminal wrongs. So stated, however, these views do not tell
us what the value of fulfilling each function actually is. The punitive
view tells us nothing about what justifies criminal punishment. The
curial view tells us nothing about the value of calling people to
account in criminal courts. The preventive view tells us nothing about
the value of preventing crime. A general justification of criminal law
fills this explanatory gap.




We can make progress by distinguishing between value of different
kinds. Some value is relational--it exists in virtue of
relationships in which people stand. That a relationship has such
value is a reason to do what will bring it into existence. The value
of friendship is a reason to make friends. The value of egalitarian
social relations is a reason to break down barriers of status and
rank. Some argue that we have sufficient reason to have criminal law
because it helps us enter a valuable relationship: it helps transform
our relations with one another from relations of mutual dependence, to
relations of independence from the power of others (Ripstein 2009,
300-324; Thorburn 2011a, 2011b).




This argument can be developed as follows. Just as slaves are
dependent on their masters, so we are dependent on one another in the
absence of a framework of legal rights: just as masters wrong their
slaves, however well they treat them, so we are doomed to wrong one
another if no such framework exists. To avoid this, we need more than
just rights that exist on paper. We need sufficient assurance that our
rights will be respected, and we need a mechanism by which their
supremacy can be reasserted in the face of wilful violation. Criminal
law's value lies in giving us what we need. Criminal punishment
amounts to reassertion. Crime prevention provides reassurance. At the
level of function, this is what the last section called a mixed view.
But the value of fulfilling both functions is one and the same: it is
the value of securing our independence from one another, so we cease
to relate to one another as master and slave, and begin to do so as
independent beings. As it is often associated (rightly or wrongly)
with Kant's political philosophy, we can call this *the
Kantian view*.




It is sometimes suggested that criminal law's general
justification is exhausted by its contribution to our independence. It
is not clear why we should accept this claim. One source of doubt is
the fact that some agents are *unavoidably*
dependent--they lack the capacities required to live as
independent beings. This is true of some non-human animals, and some
of those with serious disabilities. Precisely because of the
capacities they lack, these agents are especially vulnerable to being
abused or exploited. Part of criminal law's general
justification is that it protects the vulnerable against such
wrongs. *Ex hypothesi*, this does nothing to secure
independence. So it is not something that can be accommodated by (the
exhaustive form of) the Kantian view (Tadros 2011b).




For defenders of the Kantian view, criminal law's value derives
from a relationship it helps create. On another view, the value of
criminal law derives from a relationship that pre-exists it: the
relationship in which we stand as members of a political community
(Duff 2011). Any such community has values in terms of which it is
understood by its members. If this self-understanding is to be more
than a charade, the community must actually value its defining
values--it must do what those values are reasons to do. Imagine
that life is one such value, and a member takes another's life.
Part of what it is for a community to value life is for it to respond
to the taking: for the killer to be required to account to fellow
members, thereby communicating the community's judgment that the
killing was wrong. Criminal law is a body of law that requires the
accounting. Functionally, this is a version of the curial view. But
the value of fulfilling that function is relational: it is the value
of making the community one that is true to itself--one that does
not betray the values in terms of which members understand what it is
and who they are (Duff and Marshall 2010, 83-84). This line of
thought lends support to what I earlier called the communitarian
view. On that view, criminal proceedings discharge secondary duties
owed to the community as a whole. That such duties are part and parcel
of a valuable form of relationship helps explains why we should think
that they exist.




One objection to the view described in the previous paragraph is that
it is unduly *conservative*. What justifies criminalizing a
wrong--on that view--is that the wrong has a pre-existing
foothold in the defining values of the community: it is because of
that foothold that failing to criminalize would be a form of
self-betrayal. Some communities, however, are characterised by
systematic
*neglect* of important values--by patriarchy, or racism, or
distributive inequality. When this is so, part of the justification for
criminalization is not that it helps the community remain true to
itself, but that it helps *transform* the community by
reconstituting it in valuable ways (Dempsey 2009; 2011). One source of
criminal law's value, on this alternative view, is its ability to help alter
social morality, such that neglected values come to be taken seriously
by community members (Green 2013a). Where this is successful, criminal
law can largely disappear from members' motivational horizons: we
come to refrain from conduct for the moral reasons that make it wrong,
without reference to the fact that the conduct is criminal.




Both versions of the relational view--Kantian and
communitarian--face another doubt. Imagine \(D\) robs \(V\). It
is plausible to think that this wrong is of concern to the criminal
law
*in its own right*. It is plausible to think that whatever
further effects it might have, preventing the wrong of murder
*itself* helps justify criminalizing murder, and bringing
criminal proceedings against murderers. On both the Kantian and
communitarian views this is not the case. What justifies criminalizing
wrongs, and bringing criminal proceedings against wrongdoers, is that
this contributes to some larger social good--to the framework of
legal rules we need for independence, or to the community remaining
true to itself. We may reasonably doubt that wrongs like murder matter
to the criminal law only for these further reasons. In claiming that
this *is* why they matter, both versions of the relational view
*instrumentalize* criminal law's concern with wrongdoing:
both hold that we have reason to prevent wrongs via the criminal law
only because this is a means of establishing healthy relations in which
all share.




The above remarks concern the kind of value that justifies having
criminal law. We can also ask who is capable of realizing that value.
On both the views sketched above, criminal law's value is
grounded in a relationship in which all stand. If that value is to be
realised, someone must act on behalf of those who stand in the
relationship. In most systems of criminal law, the job is done by the
state--agents of the state create, apply, and enforce criminal
laws. Some argue that in a legitimate system of criminal law this is
the only possibility. Criminal law's value, it is claimed, is
*essentially public*--it is value that can only be
realised, even in principle, by agents of the state. This view can be
developed in a number of ways. Consider again the Kantian view. Some
claim that coercion secures independence only if the coercer speaks for
all those coerced. Otherwise it is just another independence violation.
Only state agents can speak for all of us. So the enforcement of the
criminal law must remain in their hands (Thorburn 2011a, 98-99).
Defenders of the communitarian view tell a similar story. If the value
of criminal proceedings is that they express the community's
judgment about wrongdoing, and if only state agents can convey our
collective judgment, trials must be carried out, and punishments
imposed, by those agents (Duff 2013a, 206). On both views, it is
impossible for private persons to realise the values that justify
criminal law. If these arguments go through, they have obvious
implications for debates about the privatization of prison and police
services (Dorfman and Harel 2016). They also offer us a sense in which
criminal law theory must be political. It must face up to the question
of whether there are essentially public goods, and ask what role they
play in justifying the existence of criminal law (Harel 2014,
96-99).




Some find criminal law's general justification in value that is
neither relational nor essentially public. Consider the prevention of
harm, or the prevention of moral wrongdoing. A number of writers
appeal to one or both values to justify the existence of criminal law
(Feinberg 1987, 146-155; Alexander and Ferzan 2009, 17; Simester
and von Hirsch 2011, 29-30). Because there are wrongless harms
(think of sporting injures caused without foul play) and harmless
wrongs (think of botched conspiracies or undiscovered attempts) the
aforementioned values do not always wax and wane together. One
possibility is that criminal law's concern with wrongs is
derivative of its concern with harms: criminal law should prevent
wrongs (e.g., conspiracy to injure) when and because harm is thereby
prevented (e.g., injury itself). Another possibility is that criminal
law's concern with harms is derivative of its concern with
wrongs: criminal law should prevent harms (e.g., physical injury) when
and because those harms are wrongfully caused (e.g., by assault)
(Feinberg 1987, 151-155; Moore 1997, 647-649). A third
possibility is that harms and wrongs provide two independent sources
of general justification (compare Tadros 2016,
162-166). Whatever the answer, this preventive value is
impersonal in two ways: it is not grounded in any special
relationship; and it is value that might in principle be realised by
any of us.




Anyone who seeks criminal law's justification in the coin of
impersonal value must also account for what the criminal law does when
prevention fails. Imagine \(D\) assaults \(V\), thereby causing \(V\)
physical injury. Some claim that \(D\) thereby incurs secondary moral
duties, not in virtue of any relationship in which \(D\) stands, but
simply in virtue of facts about the wrong \(D\) committed (Moore 1997,
170-172; Tadros 2011c, 275-283). Criminal law's
responses to crime discharge these duties, it is claimed, and this is
what justifies those responses.




It is worth distinguishing between two versions of this view.
According to Moore, all culpable wrongdoers incur a duty to allow
themselves to suffer. 
 Retributive justice
 is done when punishment
imposes that suffering, and this is what justifies the imposition of
criminal punishment (Moore 1997, 70-71). Moore argues that the
suffering of culpable wrongdoers is intrinsically good. On a rival
view, suffering is always intrinsically bad. We must accept, however,
that in some cases not all suffering can be avoided. Sometimes we must
choose between wrongdoers suffering now and others suffering at the
hands of wrongdoers later. Only by imposing the former can we protect
against the latter. It might look as though punishing wrongdoers for
these protective reasons amounts to treating them as mere means. But
this is not necessarily so. Tadros argues that some wrongdoers incur
duties to protect others at the cost of some harm to themselves. We
can justify imposing punishments that come at this cost to these
wrongdoers, when the punishments protect others by preventing future
wrongs. As those punished are only doing their duty, we can reasonably
claim that they are not treated as mere means (Tadros 2011c; 2016).
Though Moore and Tadros disagree on many things, their views also have
something in common. Both claim that, as a matter of principle, anyone
might impose punishment that discharges wrongdoers' secondary
duties. The value to which both appeal to justify punishment is
impersonal: it is neither relational nor essentially public (Moore
2009a, 42; Tadros 2011c, 293).




General justifications of criminal law like those sketched in the last
few paragraphs face a number of criticisms. One objection has it they
are unduly *expansive*: much moral wrongdoing--even much
that generates secondary duties to suffer or protect--is no
business of the criminal law. Failing to help one's friend move
house because one is lazy is a culpable wrong. But as the failure is a
private matter--to be resolved by the friends
themselves--there is no reason for law-makers to criminalize the
wrong (Duff 2014b; Husak 2014, 215-216). There is certainly no
reason for them to criminalize it when the friends are both citizens
of another state, and the failure occurs in the other jurisdiction
(Duff 2016). Reasons to criminalize exist, as it is often put, only
where law-makers have *standing*. And the mere fact that a
wrong generates the aforementioned secondary duties does not itself
give law-makers standing to criminalize it.




According to a second objection, the focus on moral wrongdoing is
unduly *restrictive*: much that is not morally wrong--and
which generates no secondary duties--is the business of the
criminal law. According to one argument for this conclusion, the
stable existence of (almost) any valuable social institution--be
it financial, educational, familial, military, or
political--depends on widespread compliance with its rules. Under
realistic conditions, criminal liability for violation is necessary
for stability. It is the value of stable institutions, not the moral
wrongfulness of violating their rules, that justifies bringing
criminal law into existence (Chiao 2016).




A third objection returns us to the *asymmetry* discussed at
the end of section 1. Many of the powers and permissions by means of
which criminal justice is done are withheld from private persons. Most
obviously, private persons are not typically permitted to use force to
punish others for crime. Few think that this should be changed.
Vigilantism should remain criminal. If the values that justify having
criminal law are essentially public, we appear to have an easy
explanation of this fact: private persons cannot, even in principle,
realise the values that justify criminal punishment; so they should
not be permitted to punish. If those values are not essentially
public, things are more difficult. There will surely be cases in which
private persons are best placed to discharge \(D\)'s secondary
duties--in which the state will not punish \(D\), but our
imagined moot court would fine \(D\) a proportionate amount. It is not
immediately clear that those who find criminal law's general
justification in impersonal values can explain why the moot court may
not extract the money (Thorburn 2011a, 92-93).




Let us take the third objection first. If impersonal values justify
having criminal law, we have reason to opt for whichever set of legal
rules will realise those values most efficiently. If one set of powers
and permissions will achieve more of the value in question at a lower
cost, we should--all else being equal--opt for that set. Now
compare two sets of rules. One permits state officials and private
persons alike to use force to punish criminals. Another withholds the
permissions granted to the former from the latter. We have good reason
to think that the first set of rules would bring with it significant
costs. Private persons are likely to make more mistakes about who
committed crimes, and about how much punishment is appropriate for
criminality. Different private punishers are unlikely to punish
similarly placed offenders in similar amounts. And as their actions
are less easily subjected to public scrutiny, private persons are less
easily compelled to punish for the right reasons--in order to do
justice rather than settle scores, get revenge, or maximise their
profit margins (Moore 2009a, 42; Edwards forthcoming). Avoiding these costs
is a strong reason to opt for the second set of rules. True, that set
prevents proportionate punishment being imposed by our imagined moot
court. But it is plausible to think that this benefit is outweighed by
the aforementioned costs. If it is, those who appeal to impersonal
values to justify criminal law can explain why the moot court is not
permitted to force us to give up our money.




According to the second objection, what justifies having criminal law
is its role in stabilizing valuable institutions. Notice, however,
that if violating the rules of a valuable institution contributes to
its destabilization, we will often have a moral duty to conform to the
institution's rules. By preventing these wrongs, and holding
wrongdoers responsible, we stabilize the institutions. The contrast
between a general justification focused on moral wrongdoing, and one
focused on institutional stability, therefore turns out to be a false
contrast (Tadros 2016, 135). These observations help make a more
general point. We can accept that criminal law is a tool properly used
to support financial, educational, familial, military, and political
institutions. We can also accept that it is not any old
tool--that criminal law is 'a great moral machine, stamping
stigmata on its products, painfully "rubbing in" moral
judgments on the people who entered at one end as
"suspects" and emerged from the other end as condemned
prisoners' (Feinberg 1987, 155). It is precisely because
criminal law is a tool of this special kind--a 'morally
loaded sledgehammer' (Simester and von Hirsch 2011,
10)--that its general justification is plausibly found in
preventing and responding to moral wrongs (cf. Tadros 2016,
68-70).




If this kind of general justification is not too restrictive, is it
nonetheless too expansive? This was the first of the three objections
raised above. Let us grant that some moral wrongs are not the criminal
law's business. We need not infer that criminal law is
unconcerned with moral wrongness. We need only accept that there are
facts about criminalization which give law-makers a duty not to
criminalize some moral wrongs. There are many such facts, and their
force varies depending on the wrong (Simester and von Hirsch 2011,
189-211; Moore 2014). In some cases, criminalizing a wrong will
inevitably result in selective enforcement, raising concerns about
selection being made on discriminatory grounds. In others, enforcement
would necessitate gross invasions of privacy, and require the law to
take sides in conflicts better resolved by the parties themselves.
There is often value in freely choosing not to act wrongly, and in so
choosing for the right reasons, rather than because one was coerced:
criminalizing a wrong may result in this value disappearing from the
world. It will almost inevitably divert scarce resources from other
valuable priorities. And there is often reason to think that
criminalization will not result in there being less wrongdoing in the
world. Criminal conduct may be driven underground rather than made
less common. Institutions of punishment may house unseen abuse and
victimization. Ex-offenders may be driven towards crime by their
reduced prospects in life. Where reasons like these generate a duty
not to criminalize a wrong, the conduct in question is no business of
the criminal law. There is nothing here to cast doubt on the thought
that criminal law's general justification consists in
preventing, and holding people responsible for, moral wrongs.


## 4. The Limits of Criminal Law




No-one denies that some things should not be criminalized. What is
less clear is how we are to work out what these things are. One
approach is to seek *constraints* on permissible
criminalization. Even if the values that justify having criminal law
count in favour of criminalization, our reasons to do so may be
defeated by reasons that count against. A constraint identifies
conditions under which the latter reasons always win. Consider, for
example, the wrongfulness constraint:



(W)
It is only permissible to criminalize \(\phi\)ing if \(\phi\)ing
is morally wrongful conduct.



Principles like (W) give us a line we can draw without reference to
(at least some) morally salient particulars. Conduct that falls
outside the line may not be criminalized come what may. Imagine we are
considering whether to make it a crime to possess guns. Doing so will
prevent a great deal of harmful wrongdoing that cannot be prevented
otherwise. This is a powerful moral reason to criminalize. But if (W)
is sound, and gun possession is not morally wrongful, that powerful
reason is irrelevant to the decision with which we are faced. We are
not permitted to criminalize, however much harm criminalization would
prevent (Moore 1997, 72-73; Simester and von Hirsch 2011,
22-23; Duff 2014b, 218-222).




Some suspect that all purported constraints on criminalization fail
(Duff et al 2014, 44-52; Tadros 2016, 91-107). This is not
to say that anything goes. It is rather to say that we cannot use a
line like that drawn by (W) to work out what is permissibly
criminalized. To trace the limits of the criminal law, we must engage
in a more complex normative exercise: we must consider all morally
salient particulars of proposed criminal laws--giving those
particulars due weight in our deliberations--and thereby
determine whether each proposal should be enacted. The limits of the
criminal law cannot be traced in advance of this exercise. Instead,
they are determined by it.




The constraint to which most attention has been paid is the so-called
harm principle. It is nowadays widely recognised that there is no
single such principle. Rather, there are many harm principles (Tadros
2011a; Tomlin 2014b; Edwards 2014). One important distinction is
between the *harmful conduct principle* (HCP) and the
*harm prevention principle* (HPP):



(HCP)
It is only permissible to criminalize \(\phi\)ing if \(\phi\)ing
is harmful conduct, or conduct that unreasonably risks harm.
(HPP)
It is only permissible to criminalize \(\phi\)ing if criminalizing
\(\phi\)ing is necessary to prevent harm, and if the harm done by
criminalization is not disproportionate to the harm prevented.



These principles have very different implications. That conduct is
harmful, or unreasonably risks harm, does not show that we will
prevent a proportionate amount of harm by criminalizing
it. Conversely, we may be able to prevent harm only by criminalizing
conduct that is harmless, and that does not unreasonably risk
harm.




To see the first point, consider the use of drugs. Criminalizing use
may turn a drug into forbidden fruit that is more attractive to
potential consumers, and place production in the hands of criminal
gangs who make consumption ever more harmful. Users may become less
willing to seek medical treatment for fear of exposing their
criminality, and may end up with criminal records that lead to social
exclusion, and damage their employment prospects for years to come
(United Nations 2015). Where criminalization does have these effects,
the harm it does is out of all proportion to any harm prevented. Even
if (HCP) is satisfied, (HPP) is not.




To see the second point, consider the possession of guns. Possessing a
gun is not itself harmful. And many possess guns without unreasonably
risking harm. If one endorses (HCP), one must either weaken
one's chosen principle or accept that gun possession cannot be
criminalized. If one endorses (HPP), things are different. What
matters is not the effect of each instance of gun possession, but the
effect of criminalizing all of them: if criminalizing possession will
prevent harm that would not otherwise be prevented--and do so at
a not disproportionate cost--the fact that some owners possess
guns safely is beside the point. Whether or not (HCP) is satisfied,
(HPP) is.




Constraints like (W), (HCP), and (HPP) require clarification. To
apply (W) we need to know what makes something morally wrongful.
Plausibly enough, it is morally wrongful to \(\phi\) only if there is
decisive reason not to \(\phi\). But while this is necessary, it may not
be sufficient. I have decisive reason not to go out in the rain without
my umbrella. But it does not seem morally wrongful to do so (Tadros
2016, 11-46). Whatever the correct criterion, we must ask how
law-makers are to apply it. Are law-makers to ask whether most members
of society *believe* \(\phi\)ing to be morally wrongful--a
matter of conventional morality--or are they to ask whether this
is what members would ideally believe--a matter of critical
morality (Hart 1963; Devlin 1965)? We must also ask whether just any
morally wrongful act will do. Some wrongful acts also violate rights,
such that those who commit them wrong others. On one view, it is only
when \(\phi\)ing meets this additional test that it is permissible to
criminalize \(\phi\)ing (Feinberg 1984; Stewart 2010).




Some crimes are *mala in se*--they criminalize conduct
that is morally wrongful independently of the law. Most crimes are
*mala prohibita*--they criminalize conduct that, if morally
wrongful at all, is morally wrongful partly in virtue of the fact that
it is unlawful. Is (W) compatible with the existence of *mala
prohibita*? That depends on the extent to which changes in the law
can produce changes in morality. The rules of the road are the classic
case. Apart from the law, it is morally wrongful to drive dangerously.
Such conduct is *malum in se*. What we should do to conform to
this moral norm is not always obvious. To help, the law puts in place
rules that tell us which side of the road to drive on, when to stop,
and how fast we may go. Imagine we obey these rules. In doing so, we
drive more safely than we otherwise would have: we better conform to
the moral norm that prohibits dangerous driving. One proposal is that
it is morally wrongful to violate legal norms that have this effect:
that help us better conform to moral norms that exist independently of
the law (Gardner 2011, 19-21). *Mala prohibita* of this kind
would then be compatible with (W). Of course, things are not so
straightforward. Even if legal conformity *generally* improves
our moral conformity, there may be exceptional cases in which it does
not--in which we can violate the rules of the road without putting
anyone in danger, or in which violation helps keep everyone safe. And
there may be people for whom even the generalization is not
true--whose expertise enables them to systematically violate legal
norms without creating risks any greater than those created by the rest
of us. Can an explanation be given of why these violations are
nonetheless morally wrongful? If not, (W) implies that even morally
beneficial *mala prohibita*--like the rules of the
road--must ultimately be removed from the criminal law (Husak
2008, 103-119; Simester and von Hirsch 2011, 24-29; Wellman 2013).





To apply (HCP) and (HPP) we need a conception of harm. Most views
are comparative: we are harmed by some event if and only if that event
renders us worse off in some way relative to some baseline. One
challenge is to identify the relevant baseline. Are we harmed by an
event if we are worse than we would have been if things had been
different? If so, different how? Are we harmed if we are worse off than
we were immediately beforehand? Or should we focus not on the position
we were or would have been in, but on the position we should have been
in morally speaking (Holtug 2002; Tadros 2016, 187-200)? A second
challenge is to determine in what way we must be worse off. The wider
our answer to this question, the more likely it is that harm principles
collapse into their supposed rivals. Some say we are harmed when our
interests are set back (Feinberg 1984, 31-64). But it is plausible to
think that we have interests in avoiding disgust, annoyance, and dismay.
Many people are disgusted, annoyed, or dismayed by what they take to be
morally wrongful. On an interest-based view, they are also harmed. Any
harm principle that uses this notion of harm thus threatens to permit
criminalization of much conventional immorality (Devlin 1965). A
narrower view has it that we are harmed only if our future prospects
are reduced, because we are deprived of valuable abilities or
opportunities (Raz 1986, 413-414; Gardner 2007, 3-4; Simester and von
Hirsch 2011, 36-37). Disgust, annoyance, and offence need not--and
often do not--have this effect. So they need not be--and
often are not--harmful. But as blinding pain also need not reduce
one's prospects in life, it is arguable that this view avoids
collapse only at the cost of underinclusion (Tadros 2016, 179-180).




Whatever view of harm we take, we must also decide whether all harms
count for the purposes of a given harm principle. People sometimes harm
themselves, they are sometimes harmed by natural events, and harm is
sometimes done consensually. Recall that if we endorse (HPP), we must
decide whether the harm criminalization prevents is proportionate to
the harm it does. Can we include all the aforementioned harms in our
calculations? Or must we only include harm done to others without their
consent (Mill 1859; Dworkin 1972; Feinberg 1986; Coons and Weber 2013)?
Some point out that whatever law-makers' aims, most criminal laws
will prevent *some* non-consensual harm (Feinberg 1986, 138-142;
Tadros 2016, 103). Be that as it may, whether we take into account
other harms remains important: where the scales would otherwise point
against criminalization, giving weight to a wider range of harms may
tip the balance decisively in its favour.




As well as asking how constraints might be clarified, we must ask how
they might be defended. One type of defence proceeds from within
our *theory of ideals.* A theory of ideals includes an account
of the values that bear upon how we should act, and of the priority
relations between those values (Hamlin and Stemplowska 2012). To see
how such a theory might generate constraints, consider (W). One
argument for that principle is the *argument from conviction*
(Simester and von Hirsch 2011, 19-20):



(1)
To criminally convict \(D\) of \(\phi\)ing is
 to censure \(D\) for having \(\phi\)ed;
(2)
To censure \(D\) for having \(\phi\)ed is to
 convey that \(D\)'s \(\phi\)ing was morally wrongful;
(3)
It is morally defamatory to send false messages about the moral
 status of \(D\)'s conduct;
[?](4)
It is impermissible to criminalize conduct
 that is not morally wrongful.



A second argument is the *argument from punishment* (Husak
2008, 92-103):



(1)
To criminally punish \(D\) is to intentionally harm
 \(D\), and expose \(D\) to social stigma;
(2)
We have a right not to be intentionally harmed
 in a way that exposes us to such stigma;
(3)
That right is permissibly infringed only if we 
 are punished for wrongful conduct;
[?](4)
It is impermissible to criminalize 
 conduct that is not morally wrongful.



One response to these arguments is that criminal law does not always
censure or stigmatize. Another is that the arguments rely on priority
claims that cannot be sustained. The argument from conviction depends
on our accepting that moral defamation cannot be justified. The
argument from punishment depends on our accepting that those who do
not act wrongly have an absolute right not to be punished. These
claims may be too strong. To test the second, think again about
possession of guns. Imagine that we criminalize possession, and that
we have good reason to think that we can thereby save many
lives. \(D\) possesses a gun safely because \(D\) likes how it looks
hanging on the wall. We can grant that \(D\) would act wrongly if
\(D\)'s conduct risked harm to others, or prevented the state
from saving others' lives. But as \(D\)'s possession is
safe, and the state has in fact criminalized possession, neither is
the case. Would the state violate \(D\)'s rights if it punished
\(D\)? It is plausible to think not. \(D\) could very easily have
refrained from possessing the gun. And if the state were to refrain
from punishing safe possessors like \(D\), more people would be likely
to possess guns in the mistaken belief that this was safe. This would
likely result in some lives being lost. The fact that not punishing
safe possessors would probably have this effect is a good reason to
think that safe possessors lack a valid complaint if they are
punished. It is a good reason to think that it sometimes *is*
permissible to punish the morally innocent. If it is, premise (3) of
the argument from punishment is false (Tadros 2016,
329-333).




Now consider (HPP). We can imagine a world in which we could flick a
switch, sending an electronic signal to \(D\)'s brain, the only
effect of which would be that \(D\) would not act wrongly. Whatever one
thinks of this means of prevention, it is not the means we utilize when
we make use of criminal law. Absent perfect compliance, criminal law
prevents wrongs by publicly making accusations, condemning people as
wrongdoers, and punishing them for their wrongs. Public accusations
often stick even if nothing comes of them. Punishment is harmful by its
very nature. The lives of \(D\)'s family and friends are collateral
damage as \(D\)'s prospects are reduced. Some claim that we can
justify causing such harm--at least when the state does the
harming--only if this is a necessary and proportionate means of
preventing people being harmed. So it is impermissible to criminalize
when this condition is not satisfied. Hence (HPP) (Raz 1986, 418-420;
Edwards 2014, 259-262).




One might reply that the harm internal to justified punishment is
harm we lack reason *not* to impose. Leaving this aside, it is
far from obvious that harm has lexical priority over other values. The
above argument for (HPP) seems to depend on this claim. But there is
wrongdoing that is both serious and harmless. Imagine \(D\) violates the
bodily integrity or sexual autonomy of an unconscious \(V\), but this is
never discovered and has no further effects (Gardner and Shute 2000;
Ripstein 2006, 218-229). It is plausible to think that the value of
preventing such wrongs, even when this does not prevent harm, is at
least sometimes capable of justifying the harm done by criminalization
(Tadros 2016, 106-107).




A second defence of constraints proceeds from within *non-ideal
theory*: from our account of what should be done when some people
will not act as they should. One might say that *all* criminal
law theory is part of non-ideal theory--that we have reason to
have criminal law precisely because people will (otherwise) act
wrongly. Be that as it may. As well as fallible agents who (would
otherwise) commit crimes, there are fallible agents who make, apply, and
enforce criminal laws. Any non-ideal theory must also take account of
the errors the latter are disposed to make. Some are errors of
application and enforcement--errors made when police officers
arrest, prosecutors charge, and courts punish the innocent. More
important for present purposes are the errors law-makers are disposed
to make when creating crimes. These errors matter here for the
following reason. Prescriptive norms are often justified on the grounds
that they prevent/mitigate errors that would be made in their absence
(Schauer 1991, 135-166). If followed, speed limits prevent some drivers
from driving in ways that are impeccable in isolation. But the limits
are justified if they prevent/mitigate errors that drivers would make
if we did without speed limits, and if preventing/mitigating the errors
is worth the cost of preventing some driving that is otherwise
impeccable. Let us grant that, when followed, constraints like (W) or
(HPP) prevent some law-makers from criminalizing in ways that are
impeccable in isolation. The constraints may be justified if they
prevent/mitigate errors law-makers would make if they did without them,
and if preventing/mitigating the errors is worth the cost of preventing
criminalization that is otherwise impeccable.




Many defenders of (HPP) offer defences that proceed in the manner
just described. One error is that of underestimating the value in lives
very different from our own: of mistaking the virtues required to
succeed in those lives for vices, and of concluding that these supposed
vices ought to be suppressed (Raz 1986, 401-407; Gardner 2007,
118-120). A second error is that of underestimating the value of
toleration. That value includes making space for experiments in living,
which both help combat prejudice by exposing people to the unfamiliar,
and help people develop deliberative faculties by exposing them to that
with which they disagree (Mill 1859; Brink 2013). A third error is that
of underestimating the harm one's policies do to those who live
in very different circumstances (Green 2013b, 202). If the main effects
of criminalizing drug use are felt in communities the affluent shun, it
is not hard to see how law-makers could be blind to the amount of
damage criminalization does. Law-makers who make each of these errors
will be tempted to create criminal laws that are anything but
impeccable--laws designed to suppress activities the value in
which has been missed, which do much more harm than their designers
anticipated. The case for (HPP) is that it stands in the way of this
temptation. Those who follow it must tolerate conduct--however
offensive or immoral they deem it to be--unless they can show that
criminalization is a necessary and proportionate means of preventing
harm.




Harm-based arguments are nowadays ubiquitous when proposed criminal
laws are discussed. Some think this shows that (HPP) is no constraint
at all (Harcourt 1999). But it is no surprise that those who merely pay
lip service to a principle are not constrained by it. The argument of
the previous paragraph was an argument that (HPP) should be
*followed*. To follow that principle is to take seriously the
need for an empirical showing--grounded in adequate
evidence--that a given law is necessary to prevent a proportionate
amount of harm. A better objection is that the error-based argument is
incomplete. How widespread would error be if law-makers took themselves
to be free of (HPP)? When are the benefits of following (HPP)--in
errors prevented--worth the costs--in otherwise impeccable
criminal laws? Might there be some other rule that brings us those
benefits at a lower cost than (HPP)? We need answers to all these
questions, and more, to know if an argument from within non-ideal
theory can support (HPP) (Tadros 2016, 94-96).




A number of other possible constraints on the criminal law have been
proposed (Dan-Cohen 2002, 150-171; Ripstein 2006). As mentioned
earlier, some are skeptical of all such principles. To determine the
limits of the criminal law, they think, we must refer to a 'more
disorderly set of considerations', none of which gives us
anything as simple as a (set of) constraint(s): the resulting account
of criminal law's limits will be 'messier' than its
rivals; but this is 'what the messy worlds in which we live
require' (Duff et al 2014, 51-52). The correct response to
this skepticism remains unclear. One possibility is that a defensible
general line can indeed be found. The question is where the line is,
and how it is to be defended against objections like those sketched
above. A second possibility is that we need the 'messier'
theory. If so, we must ask what shape that theory ought to take, and
how lofty should be the ambitions of those who construct it. We need
to know how much order can be imposed, at the theoretical level, on
the 'disorderly set of considerations' with which we are
confronted (for one answer, see Tadros 2016, 159-172). As the
criminal law's scope in many jurisdictions continues to expand
at a dizzying pace, these remain the most urgent questions facing
today's philosophers of criminal law.


## 5. Criminal Responsibility




Imagine that \(D\) takes \(V\)'s property without \(V\)'s consent.
Is \(D\) criminally responsible for the taking? Not necessarily. In English
law, \(D\) commits the offence of theft only if \(D\) acts dishonestly, and
intends for \(V\) to be deprived of her property permanently. Theft
is one of many offences commission of which depends on one's
state of mind. Elements of offences that require particular mental
states are known as *mens rea* elements. Other elements are
known as *actus reus* elements.




Some claim that if \(D\) satisfies all elements of an offence--if D
commits the *actus reus* with *mens rea*--this
suffices to make \(D\) criminally *responsible*, but not to make D
criminally *liable*. Responsibility is understood here as
answerability (Duff 2007, 19-36). While we are answerable to the courts
for committing offences, we may avoid liability by offering
satisfactory answers in the form of defences. This account of criminal
responsibility--call it *the answerability
account*--relies on a distinction between offence and defence
to which we will return. One argument for the answerability account
invokes rules of criminal procedure and evidence. To obtain a
conviction, the prosecution must prove that \(D\) committed the offence
beyond a reasonable doubt. \(D\) can safely remain silent in the absence of
such proof. If the prosecution makes its case, \(D\) has strong prudential
reasons to prove a defence: without one, \(D\) will be convicted and
punished. The best explanation of these rules, so the argument goes, is
that offending acts generate a duty to answer that is otherwise absent.
This duty explains why, when we have strong reason to believe \(D\) to be
an offender, we put \(D\) under extra rational pressure to explain herself
in court.




Some think that, on closer inspection, our rules of procedure and
evidence fail to support the answerability account, and help to
undermine it. Those rules tell prosecutors to consider evidence
*both* that \(D\) committed an offence *and* that \(D\) lacks a
defence. If there is strong evidence that \(D\) killed in self-defence, D
should not be prosecuted. This matters here for the following reason.
When prosecutors decide whether to prosecute, they are deciding whether
D should be called to answer for what \(D\) did. The fact that prosecutors
should *not* prosecute if \(D\) clearly killed in self-defence,
suggests that those who have defences are not answerable in court. It
suggests that we owe the criminal courts answers not for acts that are
*offences* but for acts that are *crimes*--for
offending acts which do not satisfy an available defence. Obviously
enough, it is for crimes that we are criminally liable. If
responsibility is answerability, and we are answerable for crimes, the
conditions of criminal responsibility and the conditions of criminal
liability are one and the same. The answerability account, as described
above, then fails (Duarte d'Almeida 2015, 239-267).


### 5.1 *Mens Rea*




On any view, the conditions under which \(D\) commits an offence are
conditions of criminal responsibility. What should these conditions
be? There has been much discussion of *the mens rea principle*
(MR):



(MR)
\(D\) should be criminally responsible for
 \(\phi\)ing only if \(\phi\)ing is partly constituted by an element
 of *mens rea*.



Standard *mens rea* requirements include intention and
recklessness. Paradigmatically, we intend \(X\) if, and only if, \(X\)
is one of our reasons for acting: if, and only if, we act in order to
bring \(X\) about. We are reckless about \(X\) if, and only if, (i) we
are aware there is a risk of \(X\), and (ii) running the risk of which
we are aware is unjustified.




Whether criminal responsibility should require *mens rea*, and
what *mens rea* it should require, both depend on the reasons
we have to accept (MR). Perhaps the most familiar defence appeals
to *the culpability principle* (C):



(C)
\(D\) should be criminally liable for \(\phi\)ing only if \(D\)
 is culpable for having \(\phi\)ed.



Culpability, as that term is used here, is a moral notion. It is
synonymous with moral fault or moral blameworthiness. *Mens rea*
is not sufficient for culpability--even intentional killings are
sometimes excused. But it may well be necessary--culpability may
presuppose at least some element of *mens rea* (Simester 2013;
cf. Gardner 2007, 227-232). If this is so, the debate shifts to whether
we should accept (C). One worry about this principle is its generality.
The consequences of criminal liability are not always especially
burdensome. And the benefits of liability without culpability may be
especially significant. To take but one example, think of regulations
that govern the activities of corporations, and which protect the
health and safety of the public at large. Making it a criminal offence
to violate these regulations, and imposing hefty fines, need have none
of the destructive effects of imprisoning individuals. Dispensing with
culpability requirements may increase the deterrent effects of the law,
by making it harder for violators to escape conviction. Whether (C) is
sound depends on whether effects like these--which, *ex
hypothesi*, protect the health and safety of many--can justify
imposing criminal liability without culpability.




That (C) may admit of exceptions does not, of course, show that (C)
is not generally sound. I suggested above that, where (C) does apply,
it entails (MR). *How much* mens rea (C) requires is a further
question. Take the offence of causing death by dangerous driving. The
*actus reus* of the crime requires two things: \(D\)'s driving
must exhibit deficiencies that we reasonably expect a qualified driver
to avoid, and those deficiencies must cause the death of another
person. Some think that (C) calls for two *mens rea*
requirements: \(D\) must have been aware of the deficiencies that made her
driving dangerous, and she must have been aware of a risk that they
would cause death. The idea that each *actus reus* element
should have a corresponding *mens rea* element is known as the
*correspondence principle* (Ashworth 2008). Whether (C) in fact
supports that principle is a matter of debate. It is sometimes the case
that the risk of causing some harmful outcome (like death) helps make
it the case that an act (like dangerous driving) is wrongful. There is
an internal connection, in these cases, between our assessment of the
act and the risk of the outcome. Some claim that where this internal
connection exists, \(D\)'s awareness that she was engaged in the
wrongful act *establishes* that she is culpable for the harmful
outcome. If this is right, \(D\) need not have any *mens rea* as to
that outcome in order to be culpable for it when it occurs: the
correspondence principle cannot be derived from (C) (Simester 2005,
44-46; Duff 2005, 143-147).




A second defence of (MR) appeals to the rule of law (RL):



(RL)
the law should be such that those to whom it applies can use its
 norms to guide their conduct.



Conformity to (RL) is a matter of degree. But an especially high
degree of conformity is expected of the criminal law. One reason for
this is the special powers criminal law confers on \(D\)'s accusers.
Another is the damage a guilty verdict does to the life of the accused.
The connection between (RL) and (MR) is clearly stated by Gardner:



> 
> 
> According to the ideal known as the rule of law, those of us about
> to commit a criminal wrong should be put on stark notice that that is
> what we are about to do. The criminal law should not ambush us
> unexpectedly. Of course, to avoid unexpected ambushes we all need to
> know what the law requires of us. For that reason, criminal laws should
> be clear, open, consistent, stable, and prospective. ... Even all
> this, however, is not enough to ensure that those of us about to
> violate the criminal law are put on stark notice that we are about to
> violate it. For we may know the law and yet have no grasp that what we
> are about to do might constitute a violation of it. That is because
> often we have no idea which actions we are about to perform. I make a
> light-hearted remark and (surprise!) I offend one of my guests. I turn
> on my oven and (surprise!) I blow all the fuses. The mens rea principle
> is the principle according to which such actions - the
> self-surprising ones - should not be criminal wrongs (Gardner
> 2005, 69-70). 




If \(D\) must be aware of those aspects of her actions that make them of
interest to the criminal law, she is less likely to be ambushed by
criminal offences that prohibit those actions. In this way, *mens
rea* requirements contribute to personal autonomy by increasing our
ability to steer our lives away from criminal conviction and
punishment. So (RL) supports (MR). Does it also support the
correspondence principle? This is less clear. One view has it that
\(D\)'s awareness of the facts that made her driving dangerous
disqualifies \(D\) from complaining that she was ambushed by liability for
\(V\)'s death (at least as long as said liability was adequately
publicized). On another view, \(D\)'s autonomy not only counts in
favour of helping \(D\) to anticipate criminal liability, it *also*
counts in favour of helping \(D\) to anticipate its legal consequences,
such that \(D\) can decide if the price of those consequences is worth
paying (Hart 1968, 47; Ashworth 2008). If it does not occur to \(D\) that
\(\phi\)ing might cause death, it also does not occur to \(D\) that \(\phi\)ing
might result in her suffering the additional punishment prescribed for
causing it. \(D\) is more likely to factor this information into her
decision-making if the criminal law insists that \(D\) is aware of the
risk--if it insists on correspondence between *actus reus*
and *mens rea*.




A third argument for (MR) appeals to liberty (Simester and Chan
2011, 393-395). Consider an offence that prohibits damaging other
people's property. If the *mens rea* requirement is one of
intent, \(D\) is free to knowingly take risks with \(V\)'s possessions.
If the *mens rea* requires awareness, \(D\) is free to put \(V\)'s
possessions in harm's way without giving thought to the risks. If
there is no *mens rea* at all, no amount of care will help \(D\) if
she causes property to be damaged. These examples help show that
*mens rea* requirements affect the range of options legally
available to \(D\). Obviously enough, the degree to which we should care
about taking options off the table depends on how much value they have.
This makes the liberty-protecting role of *mens rea* especially
important where criminal responsibility extends beyond paradigmatic
cases of wrongdoing. Consider the law of complicity. Under what
conditions should S be criminally responsible for participating in
wrongs committed by P? Imagine it is sufficient that S realises P might
act wrongly. Anyone who sells goods that are liable to misuse is then
in danger of being turned into a criminal by their customers.
Shopkeepers must run the gauntlet or close their doors. Narrower
*mens rea* requirements enable them to both stay in business and
ensure they remain on the right side of the law (Simester 2006,
591-592).




It is worth concluding this section by returning to two questions
distinguished at its outset: (i) should criminal responsibility require
*mens rea*? (ii) what *mens rea* should it require?
Question (i) is often discussed under the heading of strict liability.
The literature distinguishes between various senses in which liability
can be strict (Duff 2005; Gardner 2005, 68-69; Simester 2005, 22-23).
Criminal liability for \(\phi\)ing is *substantively* strict if we
can \(\phi\) without being culpable for \(\phi\)ing. It is *formally*
strict if \(\phi\)ing lacks elements of mens rea. This second category can
itself be subdivided. Liability is formally strict *in the strong
sense* when there is no *mens rea* element at all. Liability
is formally strict *in the weak sense* when at least one
*actus reus* element has no corresponding element of *mens
rea.* If (C) is a sound principle, criminal liability should not be
substantively strict. If (MR) is sound, there should be no criminal
liability that is formally strict in the strong sense. If the
correspondence principle is sound, liability that is formally strict in
the weak sense also should not exist.




So much for question (i). What about question (ii)? The above
discussion assumed that *mens rea* at the very least requires
awareness. But criminal liability sometimes turns not on what D
noticed, but on what \(D\) failed to notice--on circumstances that
would have caused a reasonable person to refrain from doing what \(D\) did.
It is where such circumstances exist that \(D\)'s actions are
negligent. Some writers claim that negligence has no place in criminal
law. If (C) is sound, and culpability requires awareness, then criminal
liability should require recklessness at the very least. Others take a
different view. They claim that when we are unaware of risks because of
vices like arrogance or indifference, this *makes* us culpable
for running those risks. So (C) is compatible with at least some
instances of negligence liability in criminal law (Hart 1968, 136-157;
Simester 2000, Alexander and Ferzan 2009, 69-85; Moore and Hurd
2011).


### 5.2 *Actus Reus*




Whether or not *mens rea* should be necessary for criminal
responsibility, it is rarely claimed that it should be sufficient. The
widespread belief that we should not countenance thought crimes, leads
most writers to claim that there should be an *actus reus*
element to each criminal offence. Paradigmatically, this element is
satisfied only if \(D\) acts in a way that causes some outcome, such
as death, or property damage, or fear of violence. This paradigm does,
of course, admit of a number of exceptions. As well as inchoate
offences--like attempts or conspiracies--most systems of
criminal law include liability for some omissions. Imagine \(D\) sees
\(V\) drowning in a shallow pond and chooses to do nothing. There is
no prior connection between \(D\) and \(V\). If the pond is in London,
\(D\) commits no offence. Move the drama to Paris and we have
ourselves a crime. As this example suggests, both academics and legal
systems remain divided over the positive obligations that should be
imposed by criminal law (Alexander 2002; Ashworth 2015).




Exceptions aside, the building blocks of our paradigm are each open
to interpretation. Consider, for instance, the need for causation. Is
the conclusion that \(D\) caused \(V\)'s death a matter of physical
fact--something that is, in Hume's well-known phrase, part
of the cement of the universe? Or do the rules of causation--at
least in criminal law--lie downstream of moral judgments about the
fair attribution of responsibility? Does the truth, perhaps, lie
somewhere in between? (Hart and Honore 1959; Moore 2009b;
Simester 2017). The criminal liability of many--as well as the
punishments they face--turns on the answer we give to such
questions.




Academic debate about causation and omissions largely takes our
paradigm for granted. Some writers, however, take a more radical view:
they favour a paradigm shift in our thinking about criminal
responsibility. One group of radicals focuses on outcomes. Imagine D
shoots at \(V\), intending to cause death. In any system of criminal law
this is an attempt. The radicals claim that what happens next should
make no difference: \(D\) should be convicted of the same crime whether or
not \(V\) is killed. Criminal responsibility, in short, should be
insensitive to the outcomes of what we do (Ashworth 1993; Alexander and
Ferzan 2009, 171-196). Consider again what I earlier called (C):



(C)
\(D\) should be criminally liable for \(\phi\)ing only if \(D\) is
 culpable for having \(\phi\)ed.



If this principle is sound, we can offer the following argument:



(1)
We are culpable only for what is within our control;
(2)
There are always factors that bear on the outcomes of our
 actions that we do not control;
 
[?](3)
We should not be criminally responsible
 for outcomes.



This argument relies on the following suppressed premise:



(2\('\))
We only control
 \(X\) if there is no factor that bears on \(X\) that we do not
 control.



It is only if (2\('\)) is true that we never control outcomes.
Alas, (2\('\)) has unpalatable implications. Uncontrolled factors do
not only bear on whether we succeed. They also bear on whether we try,
on the choices we make, and on the character traits that influence our
choices. (2\('\)) implies that we are never culpable for any of these
things--for our successes, our endeavours, our choices or our
character. Pursued to its logical conclusion, it implies that we are
never culpable for anything (Nagel 1979; Moore 1997, 233-246). If, as
most people believe, we sometimes *are* culpable for what we do,
(2\('\)) must be false. We can add that (3) radically understates the
conclusion of the argument offered above. When combined with (C), that
argument does not imply that we should not be criminally responsible
for outcomes. It implies that no one should ever be criminally
responsible.




We might try to salvage the argument from (1)-(3) by revising our
account of control:



(2\(''\))
We control
 \(X\) if we have a reasonable chance of preventing \(X\) or
 bringing \(X\) about.



This revision avoids the unpalatable implications of (2\('\)). But
it also renders the argument from (1)-(3) invalid. If (2\(''\))
states the correct account of control, we *do* sometimes have
control over outcomes. Imagine \(D\) holds a loaded gun to \(V\)'s head
and pulls the trigger. \(D\) has a reasonable chance--indeed, an
extremely high chance--of killing \(V\). On this account of control,
(1) and (2) do not support (3): they give us no reason to accept that
we are never criminally responsible for outcomes (Moore 2009,
24-26).


### 5.3 Defences




We have already seen that, for some, we are criminally responsible
for committing *offences* and criminally liable for committing
*crimes*. This distinction relies on a further distinction
between offences and defences: crimes are committed by those who
satisfy all the elements of an offence, without satisfying all the
elements of any available defence.




One account of the offence/defence distinction is
*procedural*. Offence elements must be proved if conviction is
to be the legally correct verdict of the court. So if absence of
consent is an offence-element--as it is in the offences created,
in England and Wales, by the Sexual Offences Act 2003--it must be
proved that consent was absent or \(D\) must be acquitted. The same is not
true of defence elements, like those that make up the defence of
duress. For a conviction to be correctly entered, it need not be proved
that \(D\) did not act under duress. It is enough that there is no evidence
that \(D\) acted under duress. The same is true where consent is a
defence-element--as it is in the offences created, in England and
Wales, by the Offences Against the Person Act 1861. If \(D\) punches \(V\) and
is charged with assault occasioning actual bodily harm, the court need
not be convinced that \(V\) did not consent. If the issue of consent never
comes up, a conviction may still be the legally correct verdict of the
court. Simply put, that \(D\) satisfied each offence element is something
that must be proved. Whether \(D\) satisfied each defence element can
remain uncertain. It is in this procedural distinction, on the view
under consideration, that the offence/defence distinction consists
(Duarte d'Almeida 2015).




This last claim is denied by those who believe that the
offence/defence distinction is *substantive*. These writers
accept that offences and defences are governed by different procedural
rules. Their claim is that the distinction between offences and
defences *explains* why those rules differ. Perhaps the most
well-known version of this view runs as follows. Offence elements are
individually necessary, and jointly sufficient, to describe an act
that there is general reason not to perform. Defence elements block
the transition from the existence of that reason to the conclusion
that \(D\) ought to be convicted of a crime. On this view, whether we
should think of the absence of consent as an element of the offence of
sexual assault, depends on whether we think that there is a general
reason not to have consensual sex with others. If there is no such
reason, the absence of consent is necessary to give us an act we have
general reason not to perform. So it is an element of the offence of
sexual assault. If, on the other hand, there *is* a general
reason not to have consensual sex, consent is properly thought of as a
defence to sexual assault (Campbell 1987; Gardner 2007,
144-149).




In addition to distinguishing between offences and defences, many
writers distinguish between types of criminal defence. The most
familiar distinction is between justifications and excuses. The most
familiar account of the distinction has it that while justified actors
deny wrongdoing, excused actors deny either responsibility or
culpability (Austin 1956; Fletcher 1978; Greenawalt 1984; Baron 2005).
Two questions are worth asking here. Is the familiar distinction worth
drawing? If so, is the familiar account of the distinction the right
way to draw it?




There are two reasons to answer the first question in the
affirmative. One invokes (C). If courts are to develop criminal
defences so that their contours track culpability, they need to know
*why* each defence makes it the case that those who plead it are
not culpable. Is there a defence of necessity because we sometimes do
the right thing by choosing the lesser of two evils? Or does the
defence exist because actors sometimes make wrongful choices under
enormous pressure, and because there is sometimes nothing culpable
about giving into the pressure? How courts should develop the defence
depends on how they answer these questions. It depends on whether they
conceive of the defence as a justification or an excuse.




A second reason to make the familiar distinction invokes the idea
that criminal trials call defendants to account. On this view, trials
are in one way continuous with life outside the law--they
institutionalize our ordinary moral practice of making and replying to
accusations (Gardner 2007, 177-200; Duff, 2010c; 2011; 2013a). When
accused of wrongdoing in our everyday lives, most of us do not only
care about whether we end up being blamed. Where we did nothing wrong,
we try to convince our accusers that this is the case: it matters to us
that others not add wrongs to the story of our lives, even if we know
that they will otherwise conclude that we acted blamelessly. There is
no reason to think that things are different in criminal courts: that
those accused of crime should, or do, care only about getting off the
hook. By retaining distinct justificatory and excusatory defences, the
criminal law gives effect to our interests in presenting
ourselves--to our accusers and to others--in the best
available rational light (Gardner 2007, 133).




Let us turn, then, to the second of our questions. Is it true that
justifications deny wrongdoing? Is it true that excuses deny
responsibility? Some think both questions should at least sometimes be
answered in the negative. True, those who act in self-defence
plausibly benefit from an exception to the duty not to harm
others. Having placed \(D\) under attack, many think, \(V\) has no
right that \(D\) not use necessary and proportionate force against
\(V\) (McMahan 2005). But the same is not true when \(D\) harms an
innocent bystander, even if this is the only way to prevent even
greater harm to others. \(V\)'s right remains, it is often
thought, but is sometimes overridden. So \(D\) still wrongs
\(V\). That wrong is justified when and because \(D\) has undefeated
reasons to commit it--reasons given by the greater harm prevented
by \(D\). If this is right, those who plead a justification do not
always deny, but sometimes concede, wrongdoing. It is the wrong that
they then try to justify (Gardner 2007, 77-82).




The familiar account might be thought to be on firmer ground when it
comes to excuses. Grant that to plead an excuse is indeed to deny
culpability. The same is true of a justification. So there is nothing
here to distinguish the two. Do excuses, then, deny responsibility? At
least sometimes, they do not. True, those who plead insanity deny that
they were capable of responding to reasons when they acted. But this
is not true of other excusatory pleas. Imagine \(T\) bursts into
\(D\)'s house and threatens to shoot \(D\) unless \(D\) shoots
\(V\). If \(D\) pleads duress, \(D\) relies on the fact that her capacity
to respond to reasons remained intact: her plea is that she
offended *in order to* avoid the harm threatened by \(T\), and in
doing so lived up to our reasonable expectations. \(D\) thereby
asserts rather than denies responsibility for an offending act
(Gardner 2007, 82-87). This does not mean that duress is a
justification. \(V\)'s right to life defeats the reasons \(D\)
has to save her own. \(D\) has a defence because we do not expect any
more from someone in \(D\)'s predicament--because we can
understand why saving her own life seemed a good enough reason to
\(D\) (Simester 2012, 105).




Two points emerge from these remarks. One is that the familiar account
of the justification/excuse distinction should be rejected. The second
is that a bipartite classification of criminal defences obscures
distinctions we have reason to make. Some respond by distinguishing
denials of responsibility (like insanity) from excuses (like duress),
and distinguishing both from justifications (like self-defence and
necessity). Excuses and justifications, so understood, are
*both* assertions of responsibility *and* denials of
culpability. Justified actors have undefeated reasons for their
actions. Excused actors live up to reasonable expectations despite
lacking such reasons (Gardner 2007, 91-139; Simester 2012, 99-108).
Though this tripartite classification is an improvement, some maintain
that further distinctions should be drawn (Duff 2007, 263-298; Simester
2012). Just how numerous the categories of criminal defence are (or
ought to be) is a topic for future work.


## 6. Criminal Procedure and Evidence




Imagine there are reasons to believe that \(D\) is criminally responsible
for having \(\phi\)ed. What may officials of the criminal justice
system do in response to those reasons? What should they do, and
refrain from doing?




As a matter of law, the answer depends on norms of criminal
procedure and evidence. Some of these norms confer powers and
permissions that help officials build their case against \(D\). Think of
stop and search, intrusive forms of surveillance, and pre-trial
detention. Other norms regulate the kinds of evidence that may be used
against \(D\) in court. Think of hearsay, or statistical evidence, or
evidence of \(D\)'s bad (or good) character (Ho 2008; Redmayne 2015).
Yet other norms govern the way in which one aspect of the criminal
justice system should respond to the misconduct of others. Imagine
evidence against \(D\) was gathered illegally, or that \(D\) was entrapped, or
that \(D\)'s case should have been discontinued according to the
guidelines prosecutors set for themselves. Should the courts throw out
\(D\)'s case, even where the evidence against \(D\) is strong? If so, on
what grounds should they do so? (Ashworth 2000; Duff et al 2007,
225-257).




The norms I have mentioned are somewhat neglected by philosophers of
criminal law. Things are different when it comes to the so-called
presumption of innocence (PI). The most well-known judicial formulation
of (PI) is found in *Woolmington v. DPP* [1935] UKHL 1:



> 
> 
> Throughout the web of the English Criminal Law one golden thread is
> always to be seen ... No matter what the charge or where the
> trial, the principle that the prosecution must prove the guilt of the
> prisoner is part of the common law of England and no attempt to whittle
> it down can be entertained. 




So understood, (PI) allocates the burden of proof in criminal trials
to those on the accusing side. Many add that \(D\)'s accusers must
meet an especially high standard of proof--they must eliminate all
reasonable doubt to secure a conviction. Though these points are widely
accepted, they leave open a range of further questions about the scope
and basis of (PI). The following remarks touch on just some (for an
overview, see Lippke 2016).




One question is whether (PI) has implications for criminal procedure
that extend beyond the criminal trial. On one view, (PI) *just
is* a norm that governs the burden and standard of proof at trial.
On another, (PI) is something more expansive: it is a norm that tells
criminal justice officials--and, perhaps, the rest of us
too--how to interact with others, including those suspected of
crime (Stewart 2014, Duff 2013b). That norm of course has implications
for the moment of trial. But its implications extend both backwards
and forwards from that point in time. They extend backwards to
decisions about whether to arrest, prosecute, or detain those
suspected of criminality (Ashworth 2006, 249; Duff 2013b,
180-185; Stewart 2014, 414). And they extend forwards to
decisions both about how much to punish (Tomlin 2014a), and about the
appropriate collateral consequences of conviction and punishment (Duff
2013b, 185-192).




A second question is whether (PI) has implications for the
substantive criminal law. Some writers--and most
courts--think not. They give (PI) a purely procedural
interpretation (Roberts 2005; Lippke 2016). It has been argued,
however, that all such interpretations are implausibly narrow (Tadros
2007; 2014; Tomlin 2013). Imagine it is an offence to possess
information of a kind that might be useful to terrorists, with the
intention of committing acts of terror. Intentions like this are often
difficult to prove. Legislators might respond by shifting the burden of
proof to D: they might make it the case that, once the prosecution
proves possession, it is for \(D\) to prove the absence of intention. The
*Woolmington* formulation suggests that this move violates (PI).
Now imagine a creative legislature simply eliminates the requirement of
intention from the law: it becomes a crime to possess information of a
kind that might be useful to terrorists, *whatever the
possessor's intentions might be*. Assuming that the
prosecution must prove every element of the revised offence, this move
brings the law into conformity with a purely procedural (PI). Now most
writers--and most human rights treaties--consider (PI) to be
an important right that protects criminal suspects against the state.
Examples like the above show that the purely procedural interpretation
has the following implication: legislators who offer suspects
*less* protection somehow *better* conform to the right.
Not only is this counterintuitive, it renders the right toothless in
the face of legislative creativity (Tadros 2014). This is, some
conclude, sufficient reason to reject the purely procedural (PI).




Imagine \(D\) is charged with a criminal offence and pleads not guilty.
On the purely procedural view, (PI) makes it a precondition of
conviction and punishment that the prosecution prove \(D\) satisfied all
elements of the offence. What those elements are is a separate
question. Some endorse a revised view that makes (PI) more demanding.
These writers distinguish between elements of offences, and the wrongs
taken by offence-creators to justify convicting and punishing
offenders. (PI), they claim, not only requires proof that \(D\) satisfied
the former; it also requires proof that \(D\) committed the latter (Tadros
2007; 2014).




To see the difference this revision makes, imagine legislators make
it an offence to possess information that might be useful to
terrorists. An intention to commit acts of terror is no element of the
offence as legislated. Our legislators do not, however, think that all
those who possess such information should be convicted and punished.
This, they know, would be ridiculous overkill. They think that
possessors who intend to commit acts of terror should be convicted and
punished. This element of intention is omitted from the offence,
because omitting it makes securing convictions easier for prosecutors,
thereby reducing the risk that those planning acts of terror will get
off the hook. (PI), on the revised view, nonetheless requires proof of
the intent: *ex hypothesi*, it is possession with an intention
to commit acts of terror that is taken by law-makers to justify
convicting and punishing offenders. To comply with (PI), criminal
courts must demand proof that \(D\) committed this wrong as a precondition
of conviction and punishment.




So understood, (PI) is anything but toothless. It is often claimed,
nowadays, that too few suspected wrongdoers are convicted of crimes,
and that new criminal laws are needed to help secure more convictions.
On the revised view, legislators can create as many criminal laws as
they want in pursuit of this objective. But no-one who pleads not
guilty may be convicted under them without proof that they are the
wrongdoers they are suspected of being. That it provides anyone who
faces criminal charges with this kind of protection against the law,
is what makes the case for the revised (PI).