## 1. Sources



The major source for Epicurean doctrine is Diogenes Laertius'
third-century C.E. *Lives of Eminent Philosophers*, a
compilation of information on the lives and doctrines of the
philosophers of classical Greece (see "Doxography of Ancient
Philosophy"). In the tenth and final book, devoted to
Epicureanism, Diogenes preserves three of Epicurus' letters to
his disciples, in which he presents his basic views in a concise and
handy form. The *Letter to Herodotus* summarizes
Epicurus' physical theory, the *Letter to Menoeceus*
offers a precis of Epicurean ethics, and the *Letter to
Pythocles* treats astronomical and meteorological matters. (There
is some doubt about whether the last is by Epicurus himself or a
follower, but there seems to be sufficient reason to attribute it to
the founder himself.) Diogenes also quotes a collection of brief
sayings, called the "Principal Beliefs" or
"Principal Doctrines" (*Kuriai Doxai*), excerpted
from the writings of Epicurus or, in some cases, of his close
associates; another such collection, partially overlapping with the
first, survives in an independent manuscript and is conventionally
called the Vatican Sayings. The purpose of both sets, like that of the
Letters, was to make the core doctrines easy to remember. Diogenes
also fills in topics not covered in the Letters, and provides a list
of Epicurus' writings and other biographical information (for
the text, see Dorandi 2013; for an English translation, Mensch 2018).




Short citations of Epicurus' works appear in other writers
(e.g., Plutarch, Sextus Empiricus, and the Greek commentators on
Aristotle), often taken out of context or presented in a polemical and
distorted fashion. (The standard edition of Epicurus' works in
Greek is Arrighetti 1973; the fullest collection of fragments and
testimonies is still Usener 1887, repr. with Italian translation,
Ramelli 2002; for translations, see Bibliography: Editions,
Translations, Commentaries). In addition, several works of Epicurus,
including parts of his major treatise, *On Nature* (*Peri
phuseos*) -- a series of lectures running to 37 papyrus
rolls -- have been recovered in damaged condition from the
library of a villa in the town of Herculaneum, which was buried in the
eruption of Mt. Vesuvius in 79 C.E. The library almost certainly
contained the working collection of Philodemus, an Epicurean
philosopher from Syria who studied in Athens and moved to Italy in the
first century B.C.E. Many of the rolls consist of Philodemus'
own writings, and provide valuable information about later issues in
the history of Epicureanism. One must be cautious about ascribing
these views to the founder himself, although the school tended to be
conservative and later thinkers embellished rather than altered
Epicurus' own teachings. New editions and translations are now
making these difficult texts available to a wider readership.



More or less contemporary with Philodemus is Lucretius (first century
B.C.E.), who composed in Latin *De rerum natura* ("On the
Nature of Things"; the title, if it is Lucretius' own, is
an adaptation of "On Nature") in six books of hexameter
verse, the meter characteristic of epic and didactic poetry. As a
dedicated Epicurean, passionate to promulgate the message of the
founder, Lucretius reproduced Epicurean doctrine faithfully (Sedley
1998; Clay 1983 allows Lucretius more originality). His poem
concentrates principally on the physical and psychological or
epistemological aspects of Epicureanism, and to a great extent omits
the ethical. From a hostile point of view, Cicero rehearsed and
criticized Epicurus' ideas, especially concerning ethics, in
several of his philosophical works, including *On Moral Ends*
(*De finibus*) and the *Tusculan Disputations*. Still
later, in the second century C.E., another Diogenes erected a large
inscription, to this day only partially excavated, in the city of
Oenoanda (in southwestern Turkey), which contained the basic tenets of
Epicureanism (authoritative edition by Smith 1993, but new fragments
have been published subsequently; see also Gordon 1996, Hammerstaedt
et alii, 2017).


## 2. Life



"Epicurus, the son of Neocles and Chaerestrata, was an Athenian
from the deme of Gargettus and the lineage of the Philaides, as
Metrodorus says in his *On Noble Families*. Heraclides, among
others, in his epitome of Sotion, says that he was raised in Samos,
since the Athenians were given parcels of land there, but came to
Athens when he was eighteen, when Xenocrates was head of the Academy
and Aristotle was still in Chalcis" (where he died in 322). So
begins the account by Diogenes Laertius (10.1). The dates for
Epicurus' birth and first move to Athens are thus 341 B.C.E. and
323 respectively. Diogenes adds that after the death of Alexander
(323), when the Athenians were expelled from Samos, Epicurus left
Athens and joined his father in Colophon (in 321), on the coast of
what is now Turkey. Here he studied philosophy under the tutelage of
Nausiphanes, a Democritean philosopher with skeptical leanings, and
author of a work called the *Tripod*, on which Epicurus
reportedly drew for his *Canon*, his principal work on
epistemology; in ethics, Nausiphanes substituted the term
*akataplexia* ("undauntability") for
Democritus' *athambie*, "fearlessness,"
as crucial to the good life, which invites comparison with
Epicurus' *ataraxia* or "imperturbability,"
though Epicurus is said to have denied having been influenced by him
(On Nausiphanes' role in transmitting elements of Democritean
doctrine to Epicurus, see Warren 2002: 160-92.)



Ten years later, Epicurus moved to Mytilene on the island of Lesbos,
and soon proceeded to Lampsacus on the nearby mainland; in both cities
he taught and gathered followers before returning again to Athens in
307/06, where he remained until his death in 270, at the age of
seventy or seventy-one. In Athens, he purchased the property that
became known as the "Garden" (later used as a name for his
school itself) and began to develop his own school in earnest.
Diogenes reports a number of slanderous stories that were circulated
by Epicurus' opponents, despite which he affirms that Epicurus
was of an extraordinarily humane disposition; this was the prevailing
view, shared even by hostile witnesses to Epicureanism. Diogenes also
records Epicurus' will (10.16-21), in which, among other
things, he made provisions for the children of his friends and
appointed a successor.


## 3. Physical Theory



Epicurus held that the elementary constituents of nature are
undifferentiated matter, in the form of discrete, solid and
indivisible particles ("atoms") below the threshold of
perception, plus empty space, that is, the complement of matter or
where matter is not (Inwood 1981, Konstan 2014; contra Sedley 1982,
who argues that space, for Epicurus, is a continuous matrix extending
uniformly throughout the universe, and is either occupied by matter or
empty). In its broad outline, Epicurus inherited this scheme from the
earlier atomists, above all Democritus. But Democritus' version
had been the object of critiques by later thinkers, especially
Aristotle, in part for incoherencies in the notion of an infinite
void, in part for problems attaching to his idea of minima, or
entities of the smallest conceivable size (see especially
*Physics* Book 6). First, freestanding entities of minimal size
could have no edges, and so no shapes, or rather would be all edge:
thus, if two minima touched, they would wholly overlap. (The same
argument applies to points in a line, which is why a line contains
points but is not composed of them, according to Aristotle.) Further,
if atoms really are conceptually indivisible, and not just physically
unsplittable, then when two atoms pass by each other it is impossible
that they should at any time be only partway past, for this would
imply a point partway along the length of the atom, which contradicts
the premise that it is a minimum. Although Aristotle does not state
the argument precisely in this form, it is apparent that a strict
conception of minimal-sized atoms entails that motion too must consist
of discontinuous quanta; and if motion, then time. Atoms must, then,
Aristotle inferred, move in discrete hops (*kinemata*),
each one occupying a single temporal minimum -- and hence, all
atoms must move at a uniform speed. An infinite void, with atoms
distributed throughout it, led to problems of its own, for it permits
no intrinsic spatial orientation and hence no account of why things
fall, as they are observed to do.



The problem for Epicurus was to find a way of explaining the natural
phenomena of bodily movement while responding to the challenges posed
by Aristotle's criticisms of Democritus' theory. Epicurus
rose to the challenge, although one cannot be certain that he was
responding directly to Aristotle's critique. (It is unclear
whether or how much philosophers of Epicurus' generation who
were not members of Aristotle's own school had access to
Aristotle's treatises.)



First, he distinguished between the atom, which by its nature cannot
be broken apart, and the minimum conceivable expanse of matter: atoms
have such minima as parts, but are not minima themselves -- there
can be no free-standing entity one minimum expanse in size. This
resolves the problem of atomic edges, and also that of how atoms can
come in different shapes and sizes (though never large enough to be
seen): to have the hooks and crevices needed to form compounds, they
can scarcely be theoretically partless. Second, Epicurus agreed that
time too is discontinuous, as is motion: Simplicius (p.
934.23-30 Diels; translation in Konstan 1989) quotes him as
affirming that it is untrue to say that an atom is moving over a
minimum interval, but only that it has moved (some scholars maintain
that this is a later innovation in the school; see especially Verde
2013). What is more, as Aristotle had argued must be the case, atoms
all move at the same velocity (the principle of *isotakheia*).
This last claim entailed difficulties of its own, such as how atoms
ever overtake each other, if they are moving in the same direction.
(Lucretius invoked the idea of a random swerve to solve this one; see
below.) But it also provided a solution to another problem, that of
entropy: for since atoms can never slow down, the universe can never
come to a halt (in modern terms, there is no loss of energy). As for
gravity, Epicurus may have had a solution to this too, and in a novel
form. If an atom just on its own cannot slow down or alter its
direction of motion, then an atom that is rising or moving in an
oblique direction cannot at some point begin to tilt or fall, unless
something blocks its progress and forces it to do so. If, however,
after a collision atoms tended to emerge in a statistically favored
direction -- that is, if the motions of all atoms after
collisions did not cancel each other out but on average produced a
vector, however small, in a given direction, then that direction would
by definition be down. The absence of a global orientation in the
universe was thus immaterial. Due to this vector, any given world
will, like our own, be similarly oriented in respect to the direction
"down." (Given the infinite expanse of the universe on
Epicurean theory -- see below -- we must expect there to be
a plurality of worlds, some like ours, some -- within limits
-- different.)



Macroscopic objects, of course, do not move at a uniform and very
great speed; the atoms within them do, but their motions are
restricted and deflected by neighboring atoms, and so they vibrate. In
the case of compound objects that are completely at rest, the
resultant of internal atomic motions is zero, relative, at least, to
the earth, which may have an average motion of its own. If so, and if
for some reason the earth's motion is slower in a downward
direction than that of objects on or near its surface -- because,
say, the earth is disk-shaped, as Epicurus held, and hence sinks more
slowly in the surrounding atomic medium, like a falling leaf --
then Epicurus could explain as well why things like stones tend to
fall to the earth's surface when let go.



Epicurus operated with a highly limited number of elementary
principles in nature -- he did not know the concept of force, for
example, or the associated ideas of attraction and repulsion among
atoms, not to mention more arcane properties -- and for all his
efforts to account for all the physical features of the world on the
basis of this theory, paradoxes remained. An excellent one is posed by
Sextus Empiricus (*Against the Physicists* = *M*
10.144-48), which at the same time gives an idea of how
Epicurean atoms were understood to behave (at least in Sextus'
time, late 2nd century C.E.). Sextus imagined two atoms
separated by a distance of nine minima, traveling at the same speed
(as atoms must) toward each other; after four temporal minima, the
atoms would be one spatial minimum apart. Then what? They cannot meet
in the middle of the remaining distance, by the very concept of a
minimum. Nor can one cross the interval before the other, without
violating the rule of equal velocity. But how, then, can they meet at
all? We do not know an Epicurean reply to this conundrum. Perhaps
atoms are always an even number of minimal spaces apart from one
another. Or else, minima are always bundled in such large quantities
that it is meaningless to speak of an odd or even number of minima
between atoms; the Stoics, at all events, held that whether the number
of stars, for example, is odd or even is absolutely or naturally
non-evident (*kathapax adela*, Sextus Empiricus *Outline of
Pyrrhonism* = *PH* 2.97, *M* 8.147; *physei
adela*, *M* 8.317-18). But Epicurus believed that
motion at the atomic level obeyed different laws from those that
appear to operate at the level of macroscopic objects (that atomic
motion is discontinuous is an example). Perhaps, then, motions over
small numbers of minima were in some sense indiscernible. Finally, it
is possible that he discounted such a puzzle as a purely mathematical
paradox, since it is recorded that he had little interest in
mathematics as a separate science from physics and believed it to be
irrelevant to the proper study of physics.



Fascinating as these questions are in their own right, Epicurus
himself does not proceed by creating an abstract model, exploring its
internal coherence, and determining its applicability to phenomena, in
the ideal manner of modern science. Rather, he begins with the
testimony of the senses, which he thinks are always reliable. These
provide a basis on which to draw conclusions either with respect to
things that still await confirmation or those that are by nature
imperceptible (*Letter to Herodotus* = *LH* 38). Thus,
in beginning his account of the physical world in this Letter, he
argues that things cannot arise out of nothing, since otherwise there
would be no need of specific seeds for specific plants and animals,
and anything whatsoever could be generated out of just any types of
material elements. Since this is not seen to happen, but reproduction
in things we can observe with our senses is in fact orderly and
determinate, spontaneous generation at any level is ruled out. The
logic is what Epicurus calls counterwitnessing: a hypothetical premise
(here, that things sometimes arise out of nothing) is eliminated
because experience tells against its conclusion (here, that the coming
into being of visible objects does not require determinate seeds or
materials). More simply, if *A* then *B*; but not
*B*, hence not *A*. One might, of course, challenge the
implication: something might arise from nothing, even if there are no
cases of chickens giving birth to horses. The important point,
however, is that Epicurus invokes the data of perception to testify
for or against the nature of elementary phenomena; he assumes a
certain uniformity of nature at all levels. So too with his next
postulate: things are not destroyed into what is not, since in that
case everything would cease to exist (and would have ceased to exist
before now, given infinite past time -- recall that nothing is
created out of nothing); but things do exist, hence the premise is
false.



As for bodies (note the plural: Epicurus does not typically speak of
matter per se) and void as the basic physical principles, the senses,
Epicurus affirms, testify to the existence of bodies, and by
calculation on the basis of the senses we infer the nature of what is
invisible, for example the atoms (*LH* 39). Here the reasoning
is based on analogy: what is evident to our senses must be true on the
microscopic level as well, at least in some respects. Void must exist,
in turn, if bodies are to be able to move, as they are seen to do.
Thus motion is the counterwitness to the non-existence of void --
an indirect argument is required since one cannot perceive empty
space. What is more, since bodies, being "full," offer
resistance and void, being empty, offers no resistance, they
complement each other and exhaust the possibilities; hence it is
impossible to conceive of anything besides these two principles, apart
from things that are accidents of them -- accidents that arise
from unions of elementary bodies in the void. (Inconceivability is
another tool in Epicurus' method of demonstration.) These
elementary bodies, then, are the atoms, which are indivisible and
inalterable, if things are not to dissolve into nothingness. The
*Letter to Herodotus* is an epitome of Epicurean doctrine, and
the arguments are crisp and abbreviated, but the reasoning is clear,
and is confirmed by the more detailed treatment in Lucretius, which
almost certainly follows Epicurus' *On Nature* (see Leone
2012). Epicurus appeals to some elementary intuitions concerning
bodies and their movement through space in order to establish the
structure of imperceptibly small things; he concludes that these must
be inalterable if nature is not to dissolve into nothing (creation
back out of nothing having already been eliminated by the argument
cited above from regularity in generation); and the basic features of
the atomic system are then in place. A similar appeal to the senses
establishes the infinity of the universe, since what is finite must
have an edge, and an edge is conceived in reference to something
beyond it. But the universe -- in Greek, the "all"
-- contains everything, and so there is nothing outside it by
which to conceive an edge. Hence, it is infinite. And if the all is
infinite, so is the void and the number of atoms as well, for
otherwise atoms would be too widely dispersed ever to meet
(*LH* 41-42).



Epicurus now has in place the fundamental constituents of his natural
world, and he might have stopped here, with atoms and void and the
denial, on the grounds of inconceivability, of any other kind of basic
physical principle. All secondary properties, such as color and taste,
will be explained as epiphenomena of atomic combinations, and
perception of things at a distance by the continual emission of
infinitesimally thin laminas from objects, which maintain the relevant
features of the source (in the case of vision, for example, the
laminas will preserve the atomic patterns specific to the color and
shape of the object) and directly stimulate the relevant sense organ.
This is a tricky thesis, and again posed puzzles: how do the lamina or
simulacra, as Lucretius called them, of a mountain enter the eye, for
example? In fragments? By somehow shrinking? We do not know the answer
to this one, but there are some plausible hypotheses (see Leone 2012;
Konstan 2020). A few more concepts fill in the picture of the natural
world: thus, Epicurus denies that there can be infinitely many kinds
of atoms, for then all shapes (which define the kinds) at any given
magnitude would be exhausted and atoms would have to reach visible
proportions, which we know that they do not (this argument depends on
the idea of minima, discussed further below); instead, the number of
kinds (i.e., shapes of various microscopic sizes) is inconceivably
large but "not strictly infinite," whereas the number of
each kind of atom is simply infinite (*LH* 55-56). This
condition is also invoked to explain why there is a limit on possible
types of combinations of atoms, and hence on the number of viable
species of things in the perceptible world: if there were infinitely
many kinds of atoms, Epicurus believed, they could combine to generate
absolutely anything -- an infinity of different sorts of
thing.



But an infinite number of solid and therefore indivisible atoms of
finitely many kinds, such as Epicurus' theory provides, are
enough to avoid the possibility of the universe crumbling into
nothing. Why did Epicurus complicate matters still further with the
doctrine that atoms themselves consist of still smaller parts in the
form of mathematically minimal expanses, as we saw above that he does?
Finite bodies, according to Epicurus, had to be composed of smaller
expanses, and if there were no lower limit in size to such expanses,
one would have to imagine traversing such a body in an infinite number
of moves -- but then, however small these infinitesimals might
be, the object that contained them, Epicurus reasoned, would have to
be infinitely large (*LH* 56-57). What are such minima
like? Epicurus asks us to think of the smallest perceptible thing. It
differs from larger visible entities in that it has no sub-parts to be
traversed with the eye: if you do attempt to visualize such sub-parts,
they simply coincide with the original perceptible minimum. Since such
minimal visible entities have no parts, they do not touch edge to edge
(edges are parts), and yet they measure out the body that contains
them, larger bodies having more such minima. By analogy with the
visible, then, we conceive of the smallest part of an atom
(*LH* 58-59). This conception resembles the way points
exist in a line, according to Aristotle, since they too do not touch,
nor can they exist independently. But Epicurean minima differ from
points in that they are physical expanses and so have extension. This
looks like a contradictory state of affairs: can we imagine, for
example, an atom consisting of just two minima? Or ten? It would be
like counting up the least visible bits of a perceptible object.
Geometrical problems arise as well, since it was known that the side
and diagonal of a cube, for example, were incommensurable, yet both
must, it would appear, be composed of finite and hence commensurable
numbers of minima. On the assumption that Epicurus was aware of and
cared about such puzzles, it has been suggested that he thought any
atom consists of a not strictly infinite, but inconceivably large
-- and so "not strictly finite" -- number of
minima (see Konstan 1989a): thus, the minimum may be imagined as the
inverse of the number of kinds of atoms postulated by Epicurus, a
quantity that takes on a quasi-technical status as a special order of
magnitude. But sufficient evidence for this hypothesis is lacking.


## 4. Psychology and Ethics



Having established the physical basis of the world, Epicurus proceeds
to explain the nature of the soul (this, at least, is the order in
which Lucretius sets things out). This too, of course, consists of
atoms: first, there is nothing that is not made up of atoms and void
(secondary qualities are simply accidents of the arrangement of
atoms), and second, an incorporeal entity could neither act on nor be
moved by bodies, as the soul is seen to do (e.g., it is conscious of
what happens to the body, and it initiates physical movement).
Epicurus maintains that soul atoms are particularly fine and are
distributed throughout the body (*LH* 64), and it is by means
of them that we have sensations (*aistheseis*) and the
experience of pain and pleasure, which Epicurus calls
*pathe* (a term used by Aristotle and others to signify
emotions instead). Body without soul atoms is unconscious and inert,
and when the atoms of the body are disarranged so that it can no
longer support conscious life, the soul atoms are scattered and no
longer retain the capacity for sensation (*LH* 65). There is
also a part of the human soul that is concentrated in the chest, and
is the seat of the higher intellectual functions. The distinction is
important, because it is in the rational part that error of judgment
enters in. Sensation, like pain and pleasure, is incorrigible just
because it is a function of the non-rational part, which does not
modify a perception -- that is, the reception of lamina emitted
from macroscopic bodies -- by the addition of opinion or
belief.



The corporeal nature of the soul has two crucial consequences for
Epicureanism. First, it is the basis of Epicurus' demonstration
that the soul does not survive the death of the body (other arguments
to this effect are presented in Lucretius 3.417-614). The
soul's texture is too delicate to exist independently of the
body that contains it, and in any case the connection with the body is
necessary for sensation to occur. From this it follows that there can
be no punishment after death, nor any regrets for the life that has
been lost. Second, the soul is responsive to physical impressions,
whether those that arrive from without in the form of laminas or
simulacra, or those that arise from internal motions of the body. No
phenomena are purely mental, in the sense of being disembodied states
or objects of pure consciousness conceived as separate from
embodiment. The elementary sensations of pleasure and pain,
accordingly, rather than abstract moral principles or abstract
concepts of goodness or badness, are the fundamental guides to what is
good and bad, since all sentient creatures are naturally attracted to
the one and repelled by the other. The function of the human mind
-- that part of the soul that is located in our chest -- is
not to seek higher things, but to maximize pleasure and minimize pain.
That is its entire objective; the risk (a substantial one) is that it
may miscalculate, since it is subject to false beliefs and errors in
cognitive processes.



Unlike other Hellenistic schools, such as those of Aristotle and the
Stoics, the Epicureans were not greatly interested in formal logic,
but they certainly needed a theory of the formation of beliefs. As far
as the ideational content of thinking -- that is, the thought of
something -- is concerned, Epicurus proposed a radically
reductive hypothesis: just as sensations occur as a result of thin
films emitted by objects that enter the appropriate sense organ, so
too some of these simulacra are fine enough to penetrate directly to
the mind (located in the chest), and that is how we imagine such
objects (e.g., gods). This process is invoked to explain not only
dream images, but many kinds of mental impression, including
impressions constituting voluntary thought: the latter occurs when we
attend to one or another of the exiguous physical films that are
continuously floating through the air. (How we manage to attend
voluntarily to whichever of these films we choose is not explained in
the surviving sources.) Imagining a thing is thus nothing more than
picking out the simulacra that have been emitted by it, and which may
endure beyond the life of the thing itself (hence we can imagine the
dead). These mental images have no privileged status, such as Plato
gave to his noetic Ideas or Forms; they are always true, but in this
do not differ from the information provided by the senses. Mistakes
occur here too when the wrong beliefs are associated with such
impressions, for example, that because we have a mental image of a
dead person it follows that he or she still exists in a ghostly form.
Epicurean physics proves that this is impossible.



A great barrier to correct thinking is language itself, which, because
it has a name for death, may suggest that death (being dead) is
something a person can experience and hence deserves to be feared.
Words must be understood in their basic sense, Epicurus says, as
opposed to what he calls "empty sounds" (*LH* 37).
The culprit in misunderstanding is always an illegitimate inference
from sensation (the latter including thoughts produced by film-like
images). An example is the belief that centaurs exist. Epicurus does
not deny that the thought of a centaur corresponds to some real
stimulus in the form of simulacra: his theory of knowledge commits him
to the view that it must. But the flimsy laminas as they float through
the air can become distorted or interfere with one another, and thus
the upper part of a human figure may get loosely attached to the lower
part of a horse's. We know that this is unreal because such a
combination is physically impossible: horses and human beings mature
at different rates, for example, and eat different foods (see
Lucretius 5.878-91; cf. Palaephatus *On Incredible Tales*
20). Beliefs about whether sensations correspond to an actually
existing thing must be tested against knowledge of the world, as
informed by Epicurean theory.



The ability to reason or calculate (*logismos*) cannot be a
function of images. It is the faculty that lets us infer by analogy
from the visible world to the invisible, and also that with which we
may recognize that not all pleasures are to be chosen at all times,
since some immediate pleasures may lead to long-term pain or harm
(*Letter to Menoeceus* = *LM* 129). What is more, one
must know something about the nature of pleasure in order to pursue it
rationally, and likewise for pain. Epicurus, it appears, uses the
terms pleasure and pain (*hedone*,
*algedon*) strictly in reference to physical
*pathe* or sensations, that is, those that are
experienced via the non-rational soul that is distributed throughout
the body. As for the rational part or mind, we have positive and
negative experiences through it too. Most prominent among the negative
mental states is fear, above all the fear of unreal dangers, such as
death. Death, Epicurus insists, is nothing to us, since while we
exist, our death is not, and when our death occurs, we do not exist
(*LM* 124-25); but if one is frightened by the empty name
of death, the fear will persist since we must all eventually die. This
fear is one source of perturbation (*tarakhe*), and is a
worse curse than physical pain itself; the absence of such fear is
ataraxy, lack of perturbation, and ataraxy, together with freedom from
physical pain, is one way of specifying the goal of life, for
Epicurus.



There are also positive states of mind, which Epicurus identifies by
the special term *khara* (joy), as opposed to
*hedone* (pleasure, i.e., physical pleasure). These
states too depend on belief, whether true or false. But Epicurus does
not treat *khara* as an end, or part of the end for living:
rather, he tends to describe the goal by negation, as freedom from
bodily pain and mental disturbance (*LM* 128). However,
happiness (*eudaimonia*), according to Epicurus, is not simply
a neutral or privative condition but rather a form of pleasure in its
own right -- what Epicurus called catastematic or (following
Cicero's Latin translation) "static" as opposed to
"kinetic" pleasure. Although the precise nature of this
distinction is debated, kinetic pleasures seem to be of the
non-necessary kind (see below), such as those resulting from agreeable
odors or sounds, rather than deriving from replenishment, as in the
case of hunger or thirst. The philosophical school known as the
Cyrenaics advocated increasing desires and seeking ever new ways of
gratifying them.



Epicurus objected that such pleasures are necessarily accompanied by
distress, for they depend upon a lack that is painful (Plato had
demonstrated the problematic nature of this kind of pleasure; see
*Gorgias* 496C-497A, *Philebus* 31E-32D,
46A-50C). In addition, augmenting desires tends to intensify
rather than reduce the mental agitation (a distressful state of mind)
that Epicurean philosophy sought to eliminate. Catastematic pleasure,
on the contrary, is (or is taken in) a state rather than a process: it
is the pleasure that accompanies well-being as such. The Cyrenaics and
others, such as Cicero, maintained, in turn, that this condition is
not pleasurable but rather neutral -- neither pleasurable nor
painful.



For Epicurus, there are some fears that are perfectly legitimate; so
too are some desires. Epicurus offers a classification of desires into
three types: some are natural, others are empty; and natural desires
are of two sorts, those that are necessary and those that are merely
natural (see Cooper 1999). Natural and necessary are those that look
to happiness, physical well-being, or life itself (*LM* 127).
Unnecessary but natural desires are for pleasant things like sweet
odors and good-tasting food and drink (and for various pleasurable
activities of sorts other than simple smelling, touching and tasting).
Empty desires are those that have as their objects things designated
by empty sounds, such as immortality, which cannot exist for human
beings and do not correspond to any genuine need. The same holds for
the desire for great wealth or for marks of fame, such as statues:
they cannot provide the security that is the genuine object of the
desire. Such desires, accordingly, can never be satisfied, any more
than the corresponding fears -- e.g., the fear of death --
can ever be alleviated, since neither has a genuine referent, i.e.,
death as something harmful (when it is present, we do not exist) or
wealth and power as salves for anxiety. Such empty fears and desires,
based on what Epicurus calls *kenodoxia* or empty belief, are
themselves the main source of perturbation and pain in civilized life,
where more elementary dangers have been brought under control, since
they are the reason why people are driven to strive for limitless
wealth and power, subjecting themselves to the very dangers they
imagine they are avoiding.



Although human beings, like everything else, are composed of atoms
that move according to their fixed laws, our actions are not wholly
predetermined -- rather than entertain such a paralyzing
doctrine, Epicurus says, it would be better to believe in the old
myths, for all their perversities (*LM* 134). What enables us
to wrest liberty from a mechanistic universe is the existence of a
certain randomness in the motion of atoms, that takes the form of a
minute swerve in their forward course (evidence for this doctrine
derives chiefly from later sources, including Lucretius and Cicero).
It is not entirely clear how the swerve operates: it may involve a
small angle of deviation from the original path, or else a slight
shift sideways, perhaps by a single minimum, with no change in
direction. The idea of such a minute veering, said to occur at no
determinate time or place, is less strange in the modern age of
quantum physics than it was in Epicurus' time, and it gave rise
to mocking critiques. More problematic today is how the swerve might
explain freedom of will -- if indeed Epicurus' idea of the
will was like our own. It did, at all events, introduce an
indeterminacy into the universe, and if soul atoms, thanks to their
fineness, were more susceptible to the effects of such deviations than
coarser matter, the swerve could at least represent a breach in any
strict predestination of human behavior. And this might have been
enough for Epicurus' purposes: he may not have invoked the
swerve in order to explain voluntary action (claiming that it is
action deriving, immediately or ultimately, from a swerve or some
swerves of the soul's atoms). He may have wished merely to
establish the possibility of action not deriving from the positions of
the soul's constituent atoms at any time plus the effects of
collisions among them resulting from their given movements at that
time. According to Lucretius (2.225-50), the swerve was also put
to use to solve a cosmological problem: if at some (as it were)
initial moment all atoms were moving uniformly in a single direction
(downward) at the same speed, it is impossible to conceive how the
process of atomic collisions could have begun, save by some such
device. This seems a curious idea: given that time, like space, was
infinite according to Epicurus, he need not have imagined a time prior
to collisions. Just possibly the tendency of atoms to emerge from
collisions in a preferred direction (by definition "down")
might lead over time to local regions of parallel motion, and the
swerve could serve to reintroduce contact among them. In any event,
Epicurus may have thought of atoms moving in some uniform direction
rather than in diverse ones as a default position for physical theory
(because of the simplicity of that hypothesis); thus he may have felt
the need to explain how the diversity of the atoms' motions
could have arisen.


## 5. Social Theory



Although our main witness for Epicurus' views on the evolution
of human society is Lucretius' poem (5.925-1457), there is
no doubt that Lucretius was following, in the main, the ideas of the
founder himself, as recorded in Epicurus' *On Nature* and
other treatises. In the beginning, human beings were solitary; they
reproduced haphazardly, could not communicate verbally, had no social
institutions, and survived because they were physically hardier than
their modern descendants. With time, the race softened, thanks in part
to the discovery of fire, in part too to the emergence of the family
and the gentler sentiments toward spouses and offspring to which the
family gave rise. At this stage, human beings were in a position to
unite in order to fend off natural dangers, such as wild beasts, and
they developed various kinds of technical skills, such as agriculture
and the building of houses, as well as language. Epicurus explains
(*LH* 75-76) that names at first arose naturally, in the
sense that as human beings experienced different affects
(*pathe*) or received various images
(*phantasmata*) they emitted air corresponding to these
stimuli; since human physical characteristics vary somewhat from place
to place, however, the sounds people produced in response to any given
stimulus similarly differed, which explains why there are many
tongues. Upon this basis, people later, nation by nation, established
certain terms by convention for the purpose of improving clarity and
brevity in communication. Finally, certain individual experts further
augmented the vocabulary by the introduction of new and specialized
words, to explain the results of their theoretical investigations.
Once language reached a developed state, people began to establish
alliances and friendships, which contributed further to collective
security.



This early form of social life had various advantages: among others,
the relative scarcity of goods prevented excessive competition
(sharing was obligatory for survival) and thereby set limits on those
unnatural desires that at a later, richer phase of society would lead
to wars and other disturbances. It would appear too that, before
language had developed fully, words more or less conformed to their
original or primitive objects, and were not yet a source of mental
confusion. But thanks to a gradual accumulation of wealth, the
struggle over goods came to infect social relations, and there emerged
kings or tyrants who ruled over others not by virtue of their physical
strength but by dint of gold. These autocrats in turn were overthrown,
and after a subsequent period of violent anarchy people finally saw
the wisdom of living under the rule of law. This might seem to
represent the highest attainment in political organization, but that
is not so for the Epicureans. For with law came the generalized fear
of punishment that has contaminated the blessings of life (Lucretius
5.1151; cf. [Philodemus] *On Choices and Avoidances* col. XII).
Lucretius at this point gives an acount of the origin of religious
superstition and dread of the gods, and although he does not relate
this anxiety directly to the fear of punishment under human law, he
does state that thunder and lightning are interpreted as signs that
the gods are angry at human sins (5.1218-25). While primitive
people in the presocial or early communal stages might have been awed
by such manifestations of natural power and ascribed them to the
action of the gods, they would not necessarily have explained them as
chastisement for human crimes before the concept of punishment became
familiar under the regime of law. People at an early time knew that
gods exist thanks to the simulacra that they give off, although the
precise nature of the gods according to Epicurus remains obscure (for
contrasting intepretations, see Konstan 2011 and Sedley 2011); but the
gods, for him, do not interest themselves in human affairs, since this
would compromise their beatitude (see Obbink 1996: 321-23).



If one does not fear the gods, what motive is there for living justly?
Where law obtains, Epicurus indicates, it is preferable not to commit
crimes, even secret ones, since there will always be anxiety over the
possibility of detection, and this will disrupt the tranquillity or
ataraxy that is the chief basis of happiness in life (see
*Principal Beliefs* = *KD* 34-35). Justice, for
Epicurus, depends on the capacity to make compacts neither to harm
others nor be harmed by them, and consists precisely in these
compacts; justice is nothing in itself, independent of such
arrangements (*KD* 31-33). According to Epicurus
(*LM* 132, *KD* 5), someone who is incapable of living
prudently, honorably, and justly cannot live pleasurably, and vice
versa. Moreover, prudence or wisdom (*phronesis*) is the
chief of the virtues: on it depend all the rest. This again sounds
calculating, as though justice were purely a pragmatic and selfish
matter of remaining unperturbed. Epicurus does not entertain the
thought experiment proposed by Plato in the *Republic*
(359C-360D), in which Plato asks whether a person who is
absolutely secure from punishment would have reason to be just. Did
Epicurus have an answer to such a challenge? He may simply have denied
that anyone can be perfectly confident in this way. Perhaps, however,
he did have a reply, but it was derived from the domain of psychology
rather than of ethics. A person who understands what is desirable and
what is to be feared would not be motivated to acquire inordinate
wealth or power, but would lead a peaceful life to the extent
possible, avoiding politics and the general fray. An Epicurean sage,
accordingly, would have no motive to violate the rights of others.
Whether the sage would be virtuous is perhaps moot; what Epicurus says
is that he would live virtuously, that is prudently, honorably, and
justly (the adverbial construction may be significant). He would do so
not because of an acquired disposition or *hexis*, as Aristotle
had it, but because he knows how to reason correctly about his needs.
Hence his desires would be limited to those that are natural (not
empty), and so easily satisfied, or at least not a source of
disturbance if sometimes unsatisfied.


## 6. The Epicurean Life



Epicurus placed an extremely high value on friendship (or love:
*philia*). A saying with rather a more poetic flair than is
Epicurus' custom runs: "Friendship goes dancing round the
world, announcing to all of us to wake up to happiness"
(*Vatican Saying* = *VS* 52). Epicurus held that a wise
man would feel the torture of a friend no less than his own, and would
die for a friend rather than betray him, for otherwise his own life
would be confounded (*VS* 56-57). These are powerfully
altruistic sentiments for a philosopher who posits as the unique goal
in life happiness based on freedom from physical pain and mental
anxiety. Epicurus could justify such an attitude by the same
prudential calculus that he uses to argue in favor of living justly:
only by living in such a way that loyalty to friends is perceived to
be a consummate value will one be able to feel secure in one's
friends, and thus maximize one's felicity. Yet this does not
seem quite what Epicurus means when he says that "friendship [or
love] had its beginning as a result of utility, but is to be chosen
[or is a virtue, if we follow the manuscript reading] for its own
sake" (*VS* 23). The question is further complicated by
the report in Cicero's *On Moral Ends* (1.66-70)
that there was a difference of opinion concerning friendship among
later Epicureans. Since human beings were originally asocial and only
later learned to form alliances and compacts, it is possible that
Epicurus means to say that this capacity for friendship arose out of
need, but that once the capacity for such feelings was acquired,
feeling them came to be valued in itself. The argument would be
similar to the modern idea that altruism could have developed as a
result of natural selection. But the evidence does not permit a firm
conclusion on this matter.



When Epicurus spoke of friendship, he may have had at least partly in
mind specifically the relationship among his followers, who seem to
have thought of themselves as friends. Epicureans were encouraged to
form communities and to observe certain rituals, although most of
these practices, such as the celebration each month of the day (the
20th) on which Epicurus was born or wearing rings bearing
an image of Epicurus, may have originated after the founder's
death. The Epicureans paid attention to problems of pedagogy as well,
laying out the best way to correct the ideas of people new to the
school and its community without cajoling or discouraging them. It
must be remembered that Epicurus understood the task of philosophy
first and foremost as a form of therapy for life, since philosophy
that does not heal the soul is no better than medicine that cannot
cure the body (Usener 1887, frag. 221). A life free of mental anxiety
and open to the enjoyment of other pleasures was deemed equal to that
of the gods. Indeed, it is from the gods themselves, via the simulacra
that reach us from their abode, that we derive our image of blessed
happiness, and prayer for the Epicureans consisted not in petitioning
favors but rather in a receptivity to this vision. (Epicurus
encouraged the practice of the conventional cults.) Although they held
the gods to be immortal and indestructible (how this might work in a
materialist universe remains unclear), human pleasure might
nevertheless equal divine, since pleasure, Epicurus maintained
(*KD* 19), is not augmented by duration (compare the idea of
perfect health, which is not more perfect for lasting longer); the
catastematic pleasure experienced by a human being completely free of
mental distress and with no bodily pain to disturb him or her is at
the absolute top of the scale. Nor is such pleasure difficult to
achieve: it is a mark precisely of those desires that are neither
natural nor necessary that they are hard to satisfy. Epicurus was
famously content with little, since on such a diet a small delicacy is
as good as a feast, in addition to which it is easier to achieve
self-sufficiency, and "the greatest benefit of self-sufficiency
is freedom" (VS 77).