## 1. Life and Works



Thomas Hobbes was born on 5 April 1588. His home town was Malmesbury,
which is in Wiltshire, England, about 30 miles east of Bristol. Very
little is known about Hobbes's mother. His father, also called
Thomas Hobbes, was a somewhat disreputable local clergyman.
Hobbes's seventeenth-century biographer John Aubrey tells the
story of how "The old vicar Hobs was a good fellow and had been
at cards Saturday all night, and at church in his sleep he cries out
'Trafells is troumps'" [i.e., clubs are trumps]
(Aubrey 1696, 1.387). The older Thomas Hobbes eventually (in 1604)
left Malmesbury, when a dispute with another clergyman, Richard Jeane,
escalated to the point of a fight in a churchyard. In Aubrey's
words: "Hobs stroke him and was forced to fly for it"
(Aubrey 1696, 1.387).



By that point the future philosopher Hobbes had himself left
Malmesbury (in 1602 or 1603), in order to study at Magdalene Hall,
Oxford. His studies there were supported by his uncle, Francis Hobbes,
who was a glover. After graduating from Oxford in February 1608,
Hobbes went to work for the Cavendish family, initially as a tutor to
William Cavendish (1590-1628), who later became the second earl
of Devonshire. Hobbes would work for the same family most of the rest
of his
 life.[1]
 His work for the Cavendish family is part of what allowed Hobbes to
think and write as he did: it gave him access to books, and
connections to other philosophers and scientists.



Hobbes's first notable philosophical works are from around 1640.
Before then he had, significantly, published in 1629 a translation of
Thucydides' *History of the Peloponnesian War* into
English. Hobbes had also interacted with various prominent
intellectual figures. On a trip around Europe in the mid-1630s, Hobbes
met Marin Mersenne in Paris. Aubrey claims that "When he
[Hobbes] was at Florence ... he contracted a friendship with the
famous *Galileo Galilei*" (Aubrey 1696, 1.366), although
curiously Hobbes's autobiographical writings do not mention
this, though they do mention meeting Mersenne. Earlier on, around
1620, Hobbes worked for some time as a secretary to Francis Bacon.



Hobbes first made a notable impact with philosophical writings in the
early 1640s. These included his *Elements of Law* and *De
Cive*. *The Elements of Law*, which Hobbes circulated in
1640, is the first work in which Hobbes follows his typical systematic
pattern of starting with the workings of the mind and language, and
developing the discussion towards political matters. *De Cive*
(1642) was Hobbes's first published book of political
philosophy. This work focuses more narrowly on the political: its
three main sections are titled "Liberty",
"Empire" and "Religion". However, *De
Cive* was conceived as part of a larger work, the *Elements of
Philosophy*. That work eventually had three parts: *De
Corpore* (1655), *De Homine* (1658), and *De Cive*
itself. *De Corpore*, which is discussed below, covers issues
of logic, language, method, metaphysics, mathematics, and physics.
*De Homine*, meanwhile, focuses on matters of physiology and
optics.



At this time Hobbes also had a series of interactions with Descartes.
In 1640 Hobbes sent to Mersenne a set of comments on Descartes's
*Discourse* and *Optics*. Descartes saw some of this,
and sent a letter to Mersenne in response, to which Hobbes also
responded. Then in 1641 Hobbes's objections were among those
published along with Descartes's *Meditations*. In these
exchanges and elsewhere, the attitudes of Hobbes and Descartes to one
another involved a curious mixture of respect and dismissal. On the
one occasion they are said to have met, in 1648, they did not get
along well (Martinich 1999, 171). In earlier letters, Descartes
suggested that Hobbes was more accomplished in moral philosophy than
elsewhere, but also that he had wicked views there (Descartes 1643,
3.230-1). Descartes also worried that Hobbes was "aiming
to make his reputation at my expense, and by devious means"
(Descartes 1641b, 100). Aubrey reports that the two "mutually
respected one another", but also that Hobbes thought that
Descartes would have been better off sticking to geometry (Aubrey
1696, 1.367).



Hobbes spent the next decade in exile in Paris, leaving England late
in 1640, and not returning until 1651. His exile was related to the
civil wars of the time. Hobbes was associated with the royalist side,
and might also have had reason to fear punishment because of his
defence of absolute sovereignty in his political philosophy. During
his time in France, Hobbes continued to associate with Mersenne and
his circle, including Pierre Gassendi, who seems to have been a
particular friend of Hobbes's. Late in his time in France,
Hobbes wrote *Leviathan*, which was published in 1651. Its
structure is somewhat similar to that of the *Elements of Law*,
though it also contains lengthy discussions of matters of scriptural
interpretation, and it is probably the most overtly polemical of
Hobbes's major works.



After his return to England in 1651, Hobbes continued to publish
philosophical works for several years. *De Corpore* was
published in 1655, and provides Hobbes's main statements on
several topics, such as method and the workings of language. *De
Homine* was published in 1658, completing the plan of the
*Elements of Philosophy*. In later years Hobbes defended his
work in a series of extended debates. These included debates with John
Wallis and Seth Ward that centred on Hobbes's alleged squaring
of the circle (Jesseph 1999), debates with John Bramhall about liberty
and necessity (Jackson 2007), and debates with Robert Boyle about the
experimental physics of the Royal Society (Shapin & Schaffer
1989). He also published a Latin edition of *Leviathan* in
1668, in which there were some significant changes and additions
relating to controversial topics, such as his treatments of the
Trinity and the nature of God. But Hobbes's attention was not on
philosophy alone. Indeed, in the 1670s he published translations of
the *Odyssey* and *Iliad*. And in the late 1660s he
wrote a history of the civil wars, *Behemoth; or, The Long
Parliament*, which was published posthumously (Hobbes 1668a).



Hobbes died on 4 December 1679 at Hardwick Hall, one of the homes of
the Cavendish family, with whom he was still associated after seventy
years.


## 2. Mind and Language



At an abstract level, *The Elements of Law*, the *Elements
of Philosophy*, and *Leviathan* all share a structure.
Hobbes begins with questions about mind and language, and works
towards questions in political philosophy. How exactly the parts of
the system are connected has long been debated. But Hobbes thinks at
least that we will better understand how individuals interact in
groups if we understand how individuals work. Thus the first part of
*The Elements of Law* is titled "Human Nature" and
the second "De Corpore Politico" (i.e., "About the
Body Politic"). Hobbes did not insist it was necessary to work
through all the issues about individuals before tackling the issues
about groups, as he acknowledged when he published the third part of
the *Elements of Philosophy* (*De Cive*) first. But he
did think it helpful. Thus even in *Leviathan*, with its focus
on political and religious matters, Hobbes starts with a story about
the workings of the mind. The first six chapters work through issues
about the senses, imagination, language, reason, knowledge, and the
passions.


### 2.1 Sense and Imagination



Hobbes is a sort of empiricist, in that he thinks all of our ideas are
derived, directly or indirectly, from
 sensation.[2]
 In addition he tells a causal story about perception, which is
largely the story of a causal chain of motions. The object causes
(immediately or mediately) pressure on the sense organ, which causes
motion inside us, all the way to the "brain and heart".
There this motion causes "a resistance, or counter-pressure, or
endeavour of the heart to deliver itself; which endeavour, because
*outward*, seemeth to be some matter without. And this
*seeming*, or *fancy*, is that which men call
sense" (Hobbes 1651, 1.4). Quite why this endeavour from inside
to out should make the sensation seem to come from outside is unclear,
for things coming from outside should be moving the other way. At any
rate, the sensation is strongly grounded in, perhaps even identical
with, the internal motions. But what, we might ask, is the quality?
What is, say, red? In this chapter Hobbes seems happy to say that red
in the object is just motions in it, and that red in us is motions in
us, which give rise to or are a certain sensation. And he seems happy
to avoid the issue of whether red itself belongs to the sensation or
the object. In the *Elements of Law*, however, he had proposed
the Galilean view that colours inhere in perceivers, not in the
objects perceived (Hobbes 1640, 2.4)



Imagination is Hobbes's next topic. His basic thought is that
our sensations remain after the act of sensing, but in a weaker way:
"after the object is removed, or the eye shut, we still retain
an image of the thing seen, though more obscure than when we see
it" (Hobbes 1651, 2.2). This is a story about how we form ideas.
More generally, imagination has a crucial role in Hobbes's
picture of the workings of the mind. One sort of imagination is what
we would now call imagination, "as when from the sight of a man
at one time, and of a horse at another, we conceive in our mind a
Centaur" (Hobbes 1651, 2.4). That is, we can take the ideas, the
faded sensations, from different experiences and combine them
together. But Hobbes also connects imagination, and "the faculty
of imagining" (Hobbes 1651, 2.10) closely to memory and to
understanding. Imagination and memory, Hobbes says, are the same
thing, with two names that point to different aspects of the
phenomenon of decaying sense. If we want to point to the idea or image
itself, we use 'imagination', but if we want to point to
the decay, we use 'memory' (Hobbes 1651, 2.3).



Moreover, Hobbes thinks that understanding is a sort of imagination.
That is, the faculty of imagining is responsible for understanding, as
well as for compounding images and for memory. Understanding is,
Hobbes says, "[t]he imagination that is raised in man (or any
other creature endued with the faculty of imagining) by words or other
voluntary signs" (Hobbes 1651, 2.10). Understanding is not
restricted to humans. So, for example, "a dog by custom will
understand the call ... of its master" (Hobbes 1651, 2.10).
But humans have a sort of understanding that other creatures lack. A
dog, for instance, can understand the will of its owner, say that its
owner wants it to sit down. In general, the understanding that
non-human animals can have is the understanding of will. But humans
can also understand the "conceptions and thoughts" (Hobbes
1651, 2.10) of others from their uses of language.



Understanding is for Hobbes the work of the faculty of imagination,
and crucially involves language. An account of the workings of
language is thus crucial for his having an account of the workings of
the mind. For Hobbes, the mind contains sense, imagination, and the
workings of language, and no further rational faculty, such as the
Cartesian immaterial mind that can grasp natures by clear and distinct
perception. His story about sensation, the formation of ideas, and the
workings of imagination is supposed to explain how some of our thought
works. But only with the further story about language and
understanding in place does he have a full alternative to
Descartes's story about our cognitive faculties. For Descartes,
sense and imagination are, as in Hobbes's story, closely
connected to the workings of the brain, but higher cognitive functions
are performed by the immaterial mind. Hobbes denies the existence of
that immaterial mind, and needs other accounts of those functions.
This - combined no doubt with some independent interest in the
topic - leads to Hobbes devoting a fair amount of attention to
issues in the philosophy of language.


### 2.2 Signification



Hobbes's account of language is crucial for his account of the
mind, and has important connections to his views in political
philosophy (Pettit 2008). Reading Hobbes's various accounts of
language, it quickly becomes clear that the notion of signification is
central. It is apparently the central semantic relationship in
Hobbes's story, playing the sort of role that's played in
more recent accounts by meaning or sense or reference (Abizadeh 2015;
Pecharman 2004). But what is signification? One important
question here is whether and how Hobbes distinguishes signification
(and the thing signified) from naming (and the thing named).



When Hobbes introduces his story about names in the *The Elements
of Law* he tells us that "A NAME or APPELLATION therefore is
the voice of a man, arbitrarily imposed, for a mark to bring to his
mind some conception concerning the thing on which it is imposed.
Things named are either the objects themselves, as man; or the
conception itself that we have of man, as shape or motion; or some
privation, which is when we conceive that there is something which we
conceive, not in him" (Hobbes 1640, 5.2-3). That is,
Hobbes first introduces names as having a private use for individuals,
to help them to bring particular ideas to mind. (Hobbes uses
'name' in a very broad sense. In that chapter alone, he
gives 'Socrates', 'Homer', 'man',
'just', 'valiant', 'strong',
'comely', and 'faith' as example of names.)
Notice here that though the point of using names is to recall ideas,
the thing named is not necessarily an idea. It may well be an external
object such as, in Hobbes's example, a man. Later in that
chapter, Hobbes starts to talk explicitly about signifying rather than
naming. Thus in talking about ambiguity Hobbes says that "the
word faith sometimes signifieth the same with belief; sometimes it
signifieth particularly that belief which maketh a Christian; and
sometimes it signifieth the keeping of a promise" (Hobbes 1640,
5.7). However, it is not at all clear that he really means to
introduce signifying as a relation distinct from naming here. Indeed,
he seems rather to be giving the same relation two different
names.



In *Leviathan* and *De Corpore* something more complex
goes on (Duncan 2011). The equivalent chapters in *Leviathan*
and *De Corpore* start in the same way, with discussions of the
role of names as marks to aid the memory (Hobbes 1651, 4.3; Hobbes
1655, 2.1). However, both then go straight on to introduce another
role for names, as signs to the hearer of the speaker's thoughts
(Hobbes 1651, 4.3; Hobbes 1655, 2.2-5). And
'signify' appears to be the verb corresponding to what
signs do. Though there are hints of this account in
*Leviathan*, it is set out in most detail in *De
Corpore*. There Hobbes says that names alone are not signs:
"they are not signs except insofar as they are arranged in
speech and are its parts" (Hobbes 1655, 2.3). So when we talk
about signification, it's the act of signifying, of
communicating one's thoughts by using words that are a sign of
them, that is basic. In other terminology, while words name things,
it's utterances that have signification.



Someone might think that, and nevertheless have a derivative notion of
what a word signifies. Hobbes takes some steps in this direction. In
particular, we can understand two words having the same signification
as their being interchangeable without changing the signification of
the utterance (Hungerland and Vick 1981, 68). Thus Hobbes uses
'signify' when talking about a translation relation, as
when he says in *Leviathan* that "the Greeks call it
*fancy*, which signifies *appearance*" (Hobbes
1651, 2.2). And some interpreters go further, and take Hobbes to
believe that words signify ideas, which are the ideas they call to
mind when used in utterances.


### 2.3 Nominalism



Hobbes is a nominalist: he believes that the only universal things are
names (Hobbes 1640, 5.6-7; Hobbes 1651, 4.6-8; Hobbes
1655, 2.9). The word 'tree' is, Hobbes thinks, a universal
or common name that names each of the trees. There is one name, and
there are many trees. But there is not, Hobbes argues, some further
thing that is the universal tree. Nor is there some universal idea
that is somehow of each or all of the trees. Rather,
'tree' names each of the trees, each of the individuals to
which the term applies (not, note, the collection of them).



What Hobbes calls common names, those words which apply to multiple
things, are applied because of similarities between those things, not
because of any relation to a universal thing or idea. There are, in
the minds of speakers, ideas related to those names, but they are not
abstract or general ideas, but individual images of individual things.
I could use 'tree' now, associating it with a tall pine
tree, and tomorrow use 'tree' but have before my mind a
short beech tree. What matters, Hobbes says, is that "we
remember that vocal sounds of this kind sometimes evoked one thing in
the mind, sometimes something else" (Hobbes 1655, 2.9).



Hobbes's nominalism was recognized by his contemporaries, but
was also criticized as going too far. Leibniz put the point as
follows.



> 
> 
> Hobbes seems to me to be a super-nominalist. For not content like the
> nominalists, to reduce universals to names, he says that the truth of
> things itself consists in names and what is more, that it depends on
> the human will, because truth allegedly depends on the definitions of
> terms, and definitions depend on the human will. This is the opinion
> of a man recognized as among the most profound of our century, and as
> I said, nothing can be more nominalistic than it. Yet it cannot stand.
> In arithmetic, and in other disciplines as well, truths remain the
> same even if notations are changed, and it does not matter whether a
> decimal or a duodecimal number system is used (Leibniz 1670, 128).
> 
> 
> 



Similar worries, that Hobbes's views could not account for the
fact that the same truths can be expressed in different languages,
were expressed by Descartes in his reply to Hobbes's objections
to the *Meditations* (Descartes 1641a, 2.126) and by Henry More
in his *Immortality of the Soul* (More 1659, 133-4).
Hobbes would apparently say, given his story about signification, that
"This bag is red" has the same signification as
"Diese Tasche ist rot". However, he does endorse various
claims about aspects of language and truth being conventional and
arbitrary. Some such claims are widely agreed upon: whether we write
from left to right or right to left, for instance, and what particular
marks we choose to represent words on paper. But Hobbes also endorses
other, more controversial, claims of this sort. Most controversially
perhaps, Hobbes thinks that there is a conventionality and
arbitrariness in the way in which we divide the world up in to kinds.
Though the application of 'red' to some objects and not
others is based on similarities between those objects, the
similarities do not demand that we group exactly those objects
together under a name. That is, the groupings and kinds, though based
in similarities, are not determined by those similarities alone, but
also and primarily by our decisions, which involve awareness of the
similarities, but also an arbitrary element. This introduces an extra
arbitrary element into the truth of 'This bag is red', for
even if all the underlying similarities had been the same, we might
have, say, drawn the line between red and orange in a different place.
However, it's not at all clear that such arbitrariness gives
rise to the problematic consequences that Descartes and Leibniz think
it does (Bolton 1977).


### 2.4 Reasoning as Computation



Hobbes describes reasoning as computation, and offers sketches of the
computation that he thinks is going on when we reason. This idea might
appear to have significant connections to later views, both to some
views of Leibniz's and to more recent approaches that adopt a
computational theory of mind. This section looks at Hobbes's
presentation of the idea, and then briefly at these two possible
connections.



In *De Corpore* Hobbes first describes the view that reasoning
is computation early in chapter one. "By reasoning", he
says "I understand computation. And to compute is *to collect
the sum of many things added together at the same time, or to know the
remainder when one thing has been taken from another*. To reason
therefore is the same as *to add* or *to
subtract*" (Hobbes 1655, 1.2). In the section that follows,
Hobbes gives some initial examples of addition in reasoning, which are
examples of adding ideas together to form more complex ones. Thus
"from the conceptions of a quadrilateral figure, an equilateral
figure, and a rectangular figure the conception of a square is
composed" (Hobbes 1655, 1.3). That's but a small part of
our mental activity though. Hobbes also describes propositions and
syllogisms as sorts of addition:



> 
> 
> a syllogism is nothing other than a collection of a sum which is made
> from two propositions (through a common term which is called a middle
> term) conjoined to one another; and thus a syllogism is an addition of
> three names, just as a proposition is of two (Hobbes 1655, 4.6).
> 
> 
> 



A proposition is in a sense formed by adding the name of the predicate
to the name of the subject, so by adding 'snow' and
'white' we get 'snow is white'. (We add
'is' as well, but as Hobbes argues, it's not
necessary, for we could indicate the same thing by word order rather
than having an extra word as the copula.) In thinking about
syllogisms, think about the example "Every man is an animal;
every animal is a body; therefore every man is a body" (Hobbes
1655, 4.4). In some sense we add the propositions, or at least bits of
them: we add the subject of the first proposition to the predicate of
the second, aided in this by the middle term. 



This is an intriguing suggestion, but seems not to be very far
developed. This addition has to follow some rules, especially in the
syllogistic case. As Hobbes says, "Every man is an animal; some
animal is a quadruped; therefore, some man is a quadruped" is
"defective" (Hobbes 1655, 4.4). But its conclusion too
involves the addition of parts of the premises. Presumably syllogistic
addition, like arithmetic addition, must have its rules. And of
course, Hobbes was aware of the properties of various good and bad
arguments. But it's not clear what he added to that discussion
by bringing in the language of addition. Nor, indeed, is it clear what
he really added to his discussion of the workings of the mind by his
occasional use of such language.



Nevertheless, the notion that reasoning is computation has been
referred back to more than once. Leibniz explicitly endorsed and
developed it in one early work: "Thomas Hobbes, everywhere a
profound examiner of principles, rightly stated that everything done
by our mind is a *computation*, by which is to be understood
either the addition of a sum or the subtraction of a difference
... So just as there are two primary signs of algebra and
analytics, + and [?], in the same way there are as it were two
copulas, 'is' and 'is not'" (Leibniz
1666, 3). And the idea appears to have continued to hold some appeal
for him. Thus for example Leibniz's numerical characteristic
(Leibniz 1679) attempts in another way to use the language of addition
and subtraction to explain aspects of reasoning.



Much more recently, some philosophers discussing the computational
theory of mind have also seen connections to Hobbes's idea. The
central idea of a modern computational theory of mind is that the mind
is a sort of computer. More precisely and technically, "the
immediately implementing mechanisms for intentional laws are
*computational* ... [Computations] viewed in intension,
are mappings from symbols under syntactic description to symbols under
syntactic description" (Fodor 1994, 8). And very roughly, we
might see Hobbes as saying the same thing. There are various mental
processes (compounding ideas, forming propositions, reasoning
syllogistically) that we can describe without knowing that reasoning
is computation. But the underlying process that's making this
all work is computation, namely, addition and subtraction. The
connections seem to amount to no more than that though, so it's
at least rather over-dramatic to say that Hobbes was
"prophetically launching Artificial Intelligence"
(Haugeland 1985, 23).


## 3. Materialism



By the time of *Leviathan* and *De Corpore*, Hobbes was
convinced that human beings (including their minds) were entirely
 material.[3]
 Later on he came to think that even God was a sort of material being
(Gorham 2013, Springborg 2012). This section focuses on Hobbes's
materialism about human beings. This was not a popular or widely-held
position at the time. Hobbes, however, was a materialist. Why was he a
materialist?



We might suspect that Hobbes's story about the workings of mind
and language (e.g., in the early chapters of *Leviathan*) is
supposed to be an implicit argument for materialism.
'Look', we might take Hobbes to be saying, 'I can
explain all the workings of the mind using only material resources.
What need is there to postulate an immaterial mind when this perfectly
good, and more minimal, explanation is available?' Hobbes
perhaps suggests this when he notes that his nominalism means we do
not need to suppose there's any faculty other than imagination
in order to understand how universal thought works (Hobbes 1655, 2.9).
However, for the most part we do not find Hobbes explicitly stating
that argument. Instead he presents a series of arguments against
various opponents' beliefs in immaterial beings (including
immaterial human minds).



There is a prominent suggestion in *Leviathan* that our
discourse about incorporeal things constitutes "insignificant
speech".



> 
> 
> All other names are but insignificant sounds; and those of two sorts.
> One when they are new, and yet their meaning not explained by
> definition; whereof there have been abundance coined by schoolmen, and
> puzzled philosophers.
> 
> 
> 
> Another, when men make a name of two names, whose significations are
> contradictory and inconsistent; as this name, an *incorporeal
> body*, or (*which is all one*) an *incorporeal
> substance*, and a great number more. For whensoever any
> affirmation is false, the two names of which it is composed, put
> together and made one, signify nothing at all (Hobbes 1655,
> 4.20-1).
> 
> 
> 



Thus Hobbes apparently thinks that talk about incorporeal substances
(such as Cartesian unextended thinking things) is just nonsense. But
why does he think that? Hobbes's comment about false
affirmations suggests he thinks that 'incorporeal
substance' is insignificant because 'a substance is
incorporeal' is false. But that seems to derive the
insignificance from the truth of materialism, which is hardly going to
convince Hobbes's opponents. Hobbes does offer a supporting
argument, when he claims that 'incorporeal substance' and
'incorporeal body' are "all one". But that
premise too will be denied by his opponents, who think that there can
be substances that are not bodies, and that 'substance'
and 'body' are far from interchangeable terms.



Hobbes offers a further argument against his opponents' belief
in immaterial things in *De Corpore*, in a passage in which he
talks at length about the "gross errors" of
philosophers.



> 
> 
> But the abuse consists in this, that when some men see that the
> increases and decreases of quantity, heat, and other accidents can be
> considered, that is, submitted to reasons, as we say, without
> consideration of bodies or their subjects (which is called
> "abstraction" or "existence apart from them"),
> they talk about accidents as if they could be separated from every
> body. The gross errors of certain metaphysicians take their origin
> from this; for from the fact that it is possible to consider thinking
> without considering body, they infer that there is no need for a
> thinking body; and from the fact that it is possible to consider
> quantity without considering body, they also think that quantity can
> exist without body and body without quantity, so that a quantitative
> body is made only after quantity has been added to a body. These
> meaningless vocal sounds, "abstract substances,"
> "separated essence," and other similar ones, spring from
> the same fountain (Hobbes 1655, 3.4).
> 
> 
> 



The key mistake, Hobbes thinks, lies in moving from the observations
that we can talk about 'A' and 'B', and can
think about A without thinking about B, to the conclusion that A can
exist without B existing. Hobbes attacks various views associated with
the Scholastic Aristotelian tradition as resting on that mistake. One
aim of this critical passage is to support materialism by showing a
problem with the belief that there can be thought without a body.
Hobbes elsewhere claims that Aristotle thinks that "the human
soul, separated from man, subsists by itself", so presumably has
Aristotle and Aristotelians in mind as targets (Hobbes 1668b,
46.17).



When Hobbes talks about Aristotelian views, one might ask whether his
target is Aristotle himself, or some later Aristotelians. When Hobbes
talks about Aristotelian metaphysics in particular, his main approach
seems to be to take a certain core view to have been
Aristotle's, then to criticize both that view and the further
uses that were made of it. Hobbes's attitude to Aristotelianism
comes across forcefully in a discussion in *Behemoth* that
begins by describing Peter Lombard and John Duns Scotus as writing
like "two of the most egregious blockheads in the world"
(Hobbes 1668a, 41-2). That exchange has several elements: the
condemnation of the philosophical view as nonsensical; the claim that
some philosophers aim to confuse; and the claim that views are
promoted in order to control the public and take their money. However,
though Hobbes rejected many of the views of the Scholastic
Aristotelian tradition, his work had several connections
to it, as is illustrated by Leijenhorst 2002.



The view that there can be thought without a body is also
Descartes's view. Indeed, Hobbes may be thinking of
Descartes's argument for that view in the Sixth Meditation. A
key claim in Descartes's argument is that "the fact that I
can clearly and distinctly understand one thing apart from another is
enough to make me certain that the two things are distinct"
(Descartes 1641a, 2.54). Descartes argues, via that claim, from his
ability to clearly and distinctly conceive of mind apart from body and
vice versa, to the conclusion that mind and body are really distinct
(i.e., are two substances, not one). Abstracting away from the
details, we have an argument from the conceivability of mind without
body to the conclusion that the mind is not physical. And such an
argument is one of Hobbes's targets in the "gross
errors" passage.



However Descartes, by endorsing that argument, does not endorse the
claim that 'if I can conceive of A's existing without
B's existing, then A can exist without B existing'. He
endorses at most the weaker claim that 'if I can clearly and
distinctly conceive of A's existing without B existing, then A
can exist without B existing'. There's a special sort of
conceivability involved here, clear and distinct conceivability, which
licenses the move in this case but not in general. Hobbes's
argument seems blind to this distinction.



Overall then, something of a puzzle remains. Hobbes clearly was a
materialist about the natural world, but the explicit arguments he
offers for the view seem rather weak. Perhaps he just had a good deal
of confidence in the ability of the rapidly developing science of the
his time to proceed towards a full material explanation of the mind.
Just as his contemporary William Harvey, of whom he thought very
highly, had made such progress in explaining biological matters, so
too (Hobbes might have thought) might we expect further scientists to
succeed in explaining mental matters.


## 4. Method



Hobbes was very much interested in scientific explanation
of the world: both its practice (which he saw himself as engaged in)
and also its theory. Chapter 9 of *Leviathan* tells us
something about the differences between scientific and historical
knowledge, and the divisions between sciences. Chapter 6 of *De
Corpore* gives a much fuller treatment of issues in the philosophy
of science, issues of what Hobbes calls method. Method tells us how to
investigate things in order to achieve *scientia*, the best
sort of knowledge.



Those writing about Hobbes's method have tended to tell one or
other of two stories about the sort of method he proposes and its
historical roots. One story emphasizes the connections between
Hobbes's method and Aristotelian approaches. This has often been
developed into a story about the particular influence on Hobbes of the
works of Giacomo Zabarella, a sixteenth-century Aristotelian who
studied and taught at the University of Padua, which influence is then
often said to have been somehow mediated by Galileo. The alternative
story emphasizes the connections between Hobbes's general views
about method and the traditions of thinking about method in geometry.
Here the notions of analysis and synthesis are key. Oddly enough, both
of these stories can be connected to anecdotes that Aubrey tells about
Hobbes: on the one hand, the report that Hobbes became friendly with
Galileo while traveling in Italy, and on the other, the tale of how
Hobbes became fascinated with geometry at the age of forty after
looking at copy of Euclid's *Elements*, not believing a
proposition, and tracing back the demonstration of it and the
propositions on which it depended.



This section tells a version of the first story. (For a helpful recent
critical discussion of such an approach, see Hattab 2014.) Still, one
should note that Hobbes sometimes uses the language of mathematical
method, of analysis and synthesis, in describing his general method
(Hobbes 1655, 6.1). Several commentators have seen this, together with
his clear admiration for the successes of geometry, as evidence of a
more general use of mathematical notions in his account of method
(Talaska 1988). Adams 2019 argues that Hobbes "proceeds by a
method of synthetic demonstration" in both geometry and
political philosophy. And it might indeed be the case that both
stories about Hobbes's method (the Zabarellan and the
mathematical) have some truth to them.


 
Those writing about Hobbes often describe Zabarella's method as
having two parts, resolution and composition. Resolution moves from
the thing to be explained, which is an effect, to its causes, and then
composition brings you back from causes to effects. At a suitably
general level that is correct, but it misses much detail. Most
importantly, Zabarella's method -- as seen for instance in
his work *De Regressu* - is better described as having
three parts. A crucial though somewhat mysterious third step stands
between the move from effect to cause and that from effect to cause.
The complete sequence, the arguments from effect to cause and back
again, Zabarella calls *regressus*. This sequence improves our
knowledge, taking us from confused to clear knowledge of something.
But how do we do this? The first step is to move from having confused
knowledge of the effect to having confused knowledge of the cause.
Roughly, you need to figure out what caused the thing you're
trying to explain. The second step moves from confused to clear
knowledge of the cause. This step works, Zabarella thinks, by a sort
of intellectual examination of the cause. The aim is not just to know
what thing is the cause, but to understand that thing. The final step
then moves from the clear knowledge of the cause to clear knowledge of
the effect. That is, your new full understanding of the cause gives
you better understanding of the thing caused by it.



Chapter six of *De Corpore* is Hobbes's main work on
method. There Hobbes lays out a model of the proper form of a
scientific explanation. A proper explanation tells you three things:
what the cause is, the nature of the cause, and how the cause gives
rise to the effect. Thus Hobbes accepts the Aristotelian idea that to
have the best sort of knowledge, scientific knowledge, is to know
something through its causes. Similarities to Aristotelian theories
such as Zabarella's show up even in section one of chapter six.
Here Hobbes defines philosophy as knowledge acquired by correct
reasoning. It is both knowledge of effects that you get through
conception of their causes and knowledge of causes that you get
through conception of their visible effects. Already we see signs of
the Aristotelian picture in which you come to know the cause by
knowing the visible effect and to know the effect by knowing the
cause.



Moreover, there is perhaps in Hobbes's method something like the
middle step of *regressus*. For Hobbes, to know an effect
through its causes is to know what the causes are and how they work:
"We are said *to know scientifically* some effect
*when we know what its causes are, in what subject they are, in
what subject they introduce the effect, and how they do it*"
(Hobbes 1655, 6.1). The requirement to know how the cause works, not
just what it is, is analogous to the Zabarellan requirement to have
distinct knowledge of a cause. Knowledge that the cause exists comes
from the first step of *regressus*. Complete
*regressus*, i.e., complete explanation, requires that you make
a fuller investigation of the cause. For Hobbes, analogously, to get
to *scientia* of the effect you need to understand, not just
what the causes are, but how they work.



Comparison of Hobbes's view to Zabarella's and other more
fully Aristotelian ones is complicated by Hobbes's thinking that
all causes are efficient causes and that motion is the cause of all
change in the natural world. In a more fully Aristotelian picture,
explanations are causal, but causes can be of several sorts.
Hobbes's picture is more restrictive: to find the causes is to
find the efficient causes. Moreover, he thinks the efficient causes
are all motions, so the search for causes becomes the search for
motions and mechanisms.



For all that there do seem to be similarities between Hobbes's
method and older Aristotelian approaches, one might well wonder how
Hobbes could have come to know about Zabarella's views in
particular. One story is that Hobbes learned about this method from
Galileo, but that claim is problematic. Galileo did know about
Zabarella's ideas and other similar ones (Wallace 1984).
However, the texts of Galileo in which signs of Zabarellan ideas are
evident are early ones, but Hobbes knew Galileo's thought
through his later published works. But even if the
Zabarella-Galileo-Hobbes story is hard to support, there are other
ways in which Hobbes might have learned of Zabarella's work.
Harvey, whose work Hobbes greatly admired, and who studied at the
medical school in Padua, might also have been an intermediary (Watkins
1973, 41-2). And it's far from ridiculous to contemplate
Hobbes reading the work of the popular logician Zabarella.


## 5. Philosophy of Religion



Hobbes's views about religion have been disputed at great
length, and a wide range of positions have been attributed to him,
from atheism to orthodox Christianity. This section focuses on two
central questions: whether Hobbes believes in the existence of God,
and whether he thinks there can be knowledge from revelation. Some
important aspects of Hobbes's approach to religion are left
aside. These include religion's role in politics (Lloyd 1992),
and the question of whether God plays some fundamental role in
Hobbes's ethical system (see Warrender 1957 and Martinich 1992,
but also Nagel 1959 and Darwall 1994).



Hobbes at one point rules a good deal of religious discussion out of
philosophy, because its topics are not susceptible to the full
detailed causal explanation that is required for *scientia*,
the best sort of knowledge. "Thus philosophy excludes from
itself theology, as I call the doctrine about the nature and
attributes of the eternal, ungenerable, and incomprehensible God, and
in whom no composition and no division can be established and no
generation can be understood" (Hobbes 1655, 1.8). Also excluded
are discussion of angels, of revelation, and of the proper worship of
God. But despite these not being, strictly speaking, philosophy,
Hobbes does in fact have a good deal to say about them, most notably
in *Leviathan*. Things outside philosophy (in its strict sense)
may not be amenable to thorough causal explanation in terms of the
motions of bodies, but they may well still be within the limits of
rational discussion.



Many people have called Hobbes an atheist, both during his lifetime
and more recently. However, the word 'atheist' did not
mean the same thing in the seventeenth century as it means now. Thus
when Mintz (1962), in a study of Hobbes's critics that often
mentions atheism, summarizes the reasons those critics gave for
calling Hobbes an atheist, he lists the views



> 
> 
> that the universe is body, that God is part of the world and therefore
> body, that the Pentateuch and many other books of Scripture are
> redactions or compilations from earlier sources, that the members of
> the Trinity are Moses, Jesus, and the Apostles, that few if any
> miracles can be credited after the Testamental period, that no persons
> deserve the name of 'martyr' expect those who witnessed
> the ascension of Christ, that witchcraft is a myth and heaven a
> delusion, that religion is in fact so muddled with superstition as to
> be in many vital places indistinguishable from it, [and] that the
> Church, both in its government and its doctrine, must submit to the
> dictates of Leviathan, the supreme civil authority (Mintz 1962,
> 45).
> 
> 
> 



Thus, many of Hobbes's critics in the seventeenth century,
including those who vehemently attacked his religious views, still
thought he believed in the existence of God. They thought, however,
that he was a rather dubious sort of Christian. Other critics,
however, have thought that Hobbes in fact denied the existence of God.
This might seem a curious allegation, for Hobbes often talks about God
as existing. Certainly, to read Hobbes in this way requires one to
take some of his statements at something other than face value.



In the *Elements of Law* Hobbes offers a cosmological argument
for the existence of God (Hobbes 1640, 11.2). However, he argues, the
only thing we can know about God is that he, "first cause of all
causes", exists. Our knowledge is limited in this way because
our thoughts about God are limited: "we can have no conception
or image of the Deity". So when we seem to attribute features to
God, we cannot literally be describing God (Hobbes 1640, 11.3).
We're either expressing our inability, as when we call God
incomprehensible, or we're expressing our reverence, as when we
call God omniscient and just. The same indeed is going on when we call
God a spirit: this is not "a name of anything we
conceive", but again a "signification of our
reverence" (Hobbes 1640, 11.3).



Those three views -- support for a cosmological argument, the
belief that God is inconceivable by us, and the interpretation of
apparent descriptions of God as not really descriptions -- appear
to recur in *Leviathan* (Hobbes 1651, 11.25, 12.6-9).
However, in later work, such as the appendix to the 1668 Latin edition
of *Leviathan*, Hobbes proposes a different view. The older
Hobbes thought that we could know God to have at least one feature,
namely extension. In his *Answer to Bishop Bramhall*, Hobbes
describes God as a "corporeal spirit" (Hobbes 1662,
4.306). By this he means at least that God is extended. Indeed, Hobbes
seems to think of God as a sort of extended thing that's mixed
through the rest of the world, not being in every individual place in
the world, but able to affect all the things in the world (Hobbes
1662, 4.306-13, especially 4.309-10).



Whatever one thinks of the orthodoxy of Hobbes's earlier views
-- and one might take the holder of those views just to be a very
serious believer in the rather orthodox view that God is
incomprehensible -- this later view that God is corporeal is
strange indeed. However, Hobbes does seem in his *Answer to Bishop
Bramhall* and the Appendix to the Latin edition of
*Leviathan* to believe this strange view sincerely. Indeed, he
goes to some pains to defend this as an acceptable version of
Christianity. Whether or not one believes that, this is still on the
surface an odd theism rather than atheism.



Even if Hobbes is some sort of theist, he's a theist who is
sceptical about many widely held religious views. This is notable to
some extent in his critical reading of biblical texts, which was not
at all a standard approach at the time. Indeed, Hobbes and Spinoza
often get a good deal of credit for developing this approach.
It's notable too in his treatment of matters related to
revelation.



In chapter 2 of *Leviathan* Hobbes comes to these topics at a
slightly surprising point. In the course of discussing the workings of
imagination, he talks naturally enough about dreams. Emphasizing the
occasional difficulty of distinguishing dreams from waking life, he
turns to talk of visions. Dreams had in stressful circumstances, when
one sleeps briefly, are sometimes taken as visions, Hobbes says. He
uses this to explain a supposed vision had by Marcus Brutus, and also
widespread belief in ghosts, goblins, and the like. Later he uses it
to account for visions of God (Hobbes 1651, 32.6). And Hobbes
explicitly uses this to undermine the plausibility of claims to know
things because told by God:



> 
> 
> To say he [God] hath spoken to him in a dream is no more than to say
> that he dreamed God spake to him, which is not of force to win belief
> from any man that knows dreams are for the most part natural and may
> proceed from former thoughts ... To say he hath seen a vision, or
> heard a voice, is to say that he hath dreamed between sleeping and
> waking; for in such a manner a man doth many times naturally take his
> dream for a vision, as not having well observed his own slumbering
> (Hobbes 1651, 32.6)
> 
> 
> 



This does not rule out the possibility that God might indeed
communicate directly with an individual by means of a vision. But it
does rule out other people sensibly believing reports of such
occurrences, for the events reported are easily (and usually if not
necessarily always correctly) given a natural explanation as dreams,
which themselves have natural causes.



Hobbes takes a similarly sceptical attitude to reports of miracles.
Chapter 37 of *Leviathan* is a discussion of this topic,
centred on Hobbes's definition of a miracle as "*a work
of God* (*besides his operation by the way of nature, ordained
in the creation*), *done for the making manifest to his elect
the mission of an extraordinary minister for their
salvation*" (Hobbes 1651, 37.7). Though there is some
dispute about exactly what Hobbes is doing there, there clearly is a
good deal of talk about "false" or "pretended"
miracles, with an emphasis on the possibility of trickery, and a
warning about believing too hastily in reports of miracles. The
conclusion is weaker than that of Hume's more famous argument
about the evidence for belief in miracles, but a similar sceptical
attitude is present.



The case has often been made, however, that Hobbes was not just
somewhat sceptical about some religious claims, but actually denied
the existence of God. The idea is that, though Hobbes says that God
exists, those statements are just cover for his atheism. Moreover,
these interpreters claim, there are various pieces of evidence that
point to this hidden underlying view. Opinions differ on what the
crucial evidence of the hidden atheism is. Jesseph (2002), for
instance, argues that Hobbes's claims about a material God do
not add up. Curley (1992) argues that Hobbes's discussions of
prophecy and miracles, taken together, contain a suggestive
problem.



> 
> 
> There is (what I would take to be) a fairly obvious problem of
> circularity here: in the chapter on miracles we are to judge the
> authenticity of a miracle by the authenticity of the doctrine it is
> used to support, but in the chapter on prophecy we had to judge the
> prophet's claim to be God's spokesman by his performance
> of miracles. If Hobbes is aware of this circularity, he does not call
> attention to it. Perhaps he just did not notice it. Perhaps, as
> Strauss might have suggested, he leaves it to the reader to discover
> this for himself. (Curley 1992, SS5).
> 
> 
> 



There are some tricky general methodological questions here, about
when we can reasonably say that an author is trying to communicate a
view other than the one apparently stated. Note, however, that for
someone allegedly covering up his atheism to avoid controversy, Hobbes
took the curious approach of saying many other intensely controversial
things. He was opposed to free will and to immaterial souls, opposed
to Presbyterianism and to Roman Catholicism, and managed to have
anti-royalists thinking he was a royalist, but at least one prominent
royalist (Clarendon) thinking he supported Cromwell. This was not a
recipe for a quiet life. One might see Hobbes as thinking that these
things could be said with controversy, but God's existence only
denied with genuine danger. But one needs, at least, a fairly complex
story about Hobbes's attitudes in order to sustain the view that
he was sneakily suggesting that God didn't exist.


## 6. Reception



Hobbes was a widely read and controversial author. In many cases, the
discussion of his philosophy was about his political philosophy
(Goldie 1994, Malcolm 2002). However, Hobbes's non-political
views were also discussed. The Cambridge Platonist Ralph Cudworth, for
example, devoted considerable energy to arguing against Hobbesian
atheism and materialism. Cudworth's Cambridge colleague Henry
More was also a critic of Hobbes. Margaret Cavendish, meanwhile,
reacted to Hobbes's work and developed her own non-Hobbesian
materialism. 



One important connection is that between Hobbes's work and
Leibniz's. Of all the canonical philosophers in the period from
Descartes to Kant, Leibniz is probably the one who paid most attention
to Hobbes's work, and had the most to say about different
aspects of it. Leibniz found Hobbes's work worthy of serious
engagement, but ultimately also thought it mistaken in many ways. On
the other hand, later empiricist philosophers, in particular Locke and
Hume, develop several Hobbesian themes. Indeed, one might well speak
of Hobbes, not Locke, as the first of the British empiricists.



The best known parts of Leibniz's interaction with Hobbes are
from early in Leibniz's philosophical career, before 1686, the
year in which Leibniz wrote his 'Discourse on Metaphysics'
(Bernstein 1980; Jesseph 1998; Moll 1996, 103-36; Wilson 1997).
His criticism of Hobbes's nominalism, and his early adoption of
the view that reasoning is computation, were both discussed above.
Leibniz also paid a good deal of attention to Hobbes's views
about motion, in particular those about *conatus* or endeavour,
which have application both to physics and to mathematics. And Leibniz
twice in the 1670s wrote letters to Hobbes, though it is unclear if
Hobbes ever received them, and there is no evidence of any replies.
Leibniz continued, moreover, to engage with Hobbes's work
throughout his philosophical career, even if that engagement was never
quite as intense as it was in a brief early period. There is, for
instance, a discussion of Hobbes's views in the 1709
*Theodicy*.



Looking beyond Leibniz, we can see some close connections between the
work of Hobbes and that of Locke and Hume, both of whom were well
aware of Hobbes's views. Locke's connections to Hobbes,
though perhaps not obvious, are there (Rogers 1988). Think of
Locke's empiricism (i.e., anti-nativism), his attention to
language and its workings and related errors, his granting at least
the possibility of materialism being true, and his scepticism about
revelation. Hume, meanwhile, begins his *Treatise* with his
view about ideas being less intense copies of our sensations, a view
with a close resemblance to Hobbes's view about decaying sense.
Russell (1985; 2008) argues convincingly that Hume modelled the
structure of the *Treatise* on that of Hobbes's
*Elements of Law*. And Hume, like Hobbes, combines apparent
acceptance of a basic cosmological argument with scepticism about many
religious claims. Indeed there are enough connections that it's
plausible to speak of "the empiricism of Hobbes...,
Locke..., and Hume" (Nidditch 1975, viii), rather than of
the more conventional trio of Locke, Berkeley, and Hume.