Another important philosopher from the Hellenistic period is Epicurus. He was born in the Athenian colony of Samos in 342/41 BCE; his father was sent to the island as part of a contingent of 2,000 colonists in 352 BCE. Epicurus began studying philosophy at the age of fourteen; he went to Athens at the age of eighteen, but stayed for only a short time owing to his opposition to the measures taken by Perdiccas after the death of Alexander the Great. He went to Colophon to join his father, and in 310 BCE he took up residence in Mitylene, where he founded a school. A year later, he went to Lampsacus, where he taught for four years. After this, in 306 BCE, he returned to Athens, and purchased a house and garden, where he taught and lived with his students until his death; his teachings became known as the philosophy of the garden. After his death, his school continued under the leadership of Hermachus and, after his death, Polystratus. No essential changes were made to his philosophical views in the centuries after Epicurus' death. Diogenes Laertius, himself an Epicurean, relates the calumny that was directed against Epicurus and his philosophy, giving many examples of slanderous accusations made against him (Lives, 10.1-8), but rejects all of these as unfounded (Lives, 10.9). It is interesting that Paul encounters Stoic and Epicurean philosophers in Athens c. 50/51 CE (Acts 17:18) and that Epicurean philosophers came to be known as (practical) atheists, so that in rabbinic circles the transliterated word Epicurean was used to denote atheism.
According to the list provided by Diogenes, Epicurus wrote some 300 philosophical writings, all of which have been lost, except for three philosophical letters composed by Epicurus for the purpose of encapsulating his philosophy; these have been preserved by Diogenes in his Lives of Eminent Philosophers. (Epicurus says that his Letter to Herodotus is an epitomê or summary of his philosophical system [Lives, 10.35].) In addition, Diogenes interjects into these letters points made by Epicurus in his other works, which are no longer extant. There are also fragments of Epicurus' work quoted by other writers, who usually seek to refute his philosophy. (There was much rivalry and contentiousness among the different philosophical schools during the Hellenistic and Roman periods.) In addition, several of the more some of Epicurus' poignant sayings collected together into a work call Ta Kuria, known in English as Sovran Maxims. The Roman T. Lucretius Carus wrote an Epicurean work entitled De rerum natura (On the Nature of Things); from all indications, he was faithful to Epicurus' system, changing nothing. Other sources for a knowledge of Epicurus' philosophy include works by Cicero, Seneca and Plutarch. The available sources are, therefore, adequate to derive a complete statement of Epicureanism.
In his physics, Epicurus was heavily influenced by the atomist Democritus; in fact, one could say that Epicurus merely takes Democritean physics, and formulates a ethical theory as its complement. In general, it is true to say that there is an apologetic purpose behind Epicurus' philosophy: he aims to humanize the cosmos, to eliminate the idea that one must have recourse to God or the gods to explain anything. Rather, Epicurus seeks to explain all things on analogy with ordinary human experience. The removal of supernatural causal agents frees human beings to be who they are, and thereby be happy. In fact, Epicurus defines philosophy as "an activity which by words and arguments secures the happy life" (Sextus Empiricus, Adv. math. xi. 169).
Epicurus divides his philosophy into three parts: the canonic (to kanonikon); the physics (to phusikon) and ethics (to êthikon). Diogenes explains this division and in which works Epicurus deals with each:
It is divided into three parts: canonic, physics, ethics. Canonic forms the introduction to the system and is contained in a single work entitled The Canon. The physical part includes the entire theory of Nature: it is contained in the thirty-seven books of Of Nature and, in a summary form, in the letters. The ethical part deals with the facts of choice and aversion; this may be found in the books On Human Life, in the letters, and in his treatise Of the End. (Lives, 10.30)The canonic deals with "the standard (kriterion) and the first principle (archê) and that which is elemental (stoikeiotikon)" (Lives, 10.30). In other words, the canonic deals with epistemology. Physics concerns itself with "becoming and perishing and with nature" (Lives, 10.30), whereas ethics deals with "things to be sought and avoided, with human life and with the ends" (Lives, 10.30). Ethics aims to delineate how a person may live in a way consistent with the cosmos, which things he should pursue and which things he should avoid.
As an introduction to Epicurus' three letters and Ta Kuria, Diogenes Laertius gives a brief, but valuable summary of Epicurean epistemology. He says that the Epicureans reject as superfluous what is known as dialectic; instead they insist that physicists should be content to use ordinary terms for things (Lives 10.31). In this context, dialectic refers to specialized philosophical terminology, including formal logic. The Epicurean position is that it is sufficient to use ordinary, common-sense language to express whatever can be expressed. Diogenes explains Epirurean epistemology as follows, "Now in the canon Epicurus affirms that our sensations (tas aisthęseis) and preconceptions (tas prolępseis) and our feelings (ta pathę) are the standards (kriteria) of truth" (Lives 10.31). In other words, an appeal to one or more of these is the sole determinant of what is true.
Epicurus is an empiricist, holding that all knowledge originates in sensations (tas aisthęseis). Diogenes explains, "For all of our notions are derived from sensations, either by actual contact or by analogy, or resemblance, or composition, with some slight aid from reasoning" (Lives 10.32). Sensations are "given" to us primarily by direct contact with the sensible objects through the agency of the five sense organs. With the help of reason, by which is meant the mind, sensations received directly can be modified by analogy, which is the enlarging or diminishing of a perception or the extension of the attributes of perceptions to hypothetical entities that are not directly perceived but believed to exist, such as atoms or the gods. In addition, sensations can indirectly be given by means of resemblance, in which case a perceiver comes to know a sensible object by perceiving something that resembles it. Finally, new sensations can be composed by the imagination from elements of perceptions given in direct contact. Epicurus says that the sensations received are without reason and memory: "Every sensation, he says, is devoid of reason and incapable of memory" (10.31). By this he means that sensations are pure perceptual data that are passively received by the perceiver. For this reason, it is not the nature of a sensation as a such to be part of a reasoning process (i.e. syllogism) or to be contained in memory. In addition, as "givens" (i.e., data), any particular sensation is irrefutable, as Diogenes explains:
Nor is there anything which can refute sensations or convict them of error: one sensation cannot convict another and kindred sensation, for they are equally valid; nor can one sensation refute another which is not kindred but heterogeneous, for the objects which the senses judge are not the same; not again can reason refute them, for reason is wholly dependent on sensation; not can one sensation refute another, since we pay equal heed to all (Lives 10.31)The givenness of sensations implies that one cannot reject them as spurious or illusory; it is undeniable that one has received a sensation when one is aware of it. Not even the faculty of reason (logos) can prove that sensations are "wrong," since reason, as a faculty of judgment, exists because sensations do, having these as its objects. It is not the function of reason to refute sensations, in the sense of judging whether they have been received or not. Epicurus writes in his Ta Kuria: "If you fight against all your sensations, you will have no standard to which to refer, and thus no means of judging even those judgments which you pronounce false" (Lives, 10.146). All knowledge begins with sensations, so that, if one calls into question the reliability of sense data, one cannot think or judge.
Epicurus' theory of perception explains why sensations are irrefutable. He proposes that there are thin replicas (eidola) or films composed of atoms that are perpetually coming off sensible things, some of which come into contact with one of the sense organs, thereby producing sensations (Letter to Herodotus [Lives 10.45-50]). He writes, "There are outlines or films, which are of the same shape as solid bodies, but of a thinness far exceeding that of any object that we see....To these films we give the name of 'images' or 'idols'" (10.25-46). Sensations can only originate when these thin replicas produce movement in the mind. Vision, for example, is the result of the reception of flimsy but accurate images given off from sense objects penetrating through the eye to the mind and physically affecting it. Epicurus had similar explanations for the other senses. Sensations are irrefutable because they are effects of known causes, the efflux of atoms from external objects. The perceived films are exact replicas of the originals, so that there is no epistemological "gap" between the perception and the perceived that needs to be bridged by an intermediate object. For this reason Epicurus has a correspondence theory of knowledge: what one know quite literally corresponds to what there is to know, since knowledge is contact with a replica of the original.
In his Ta Kuria, Epicurus speaks in passing about "imaginative representations" (phantasika epibolę tęs dianoias) (Lives 10.147). Lucretius, however, sheds more light on the nature of these (On the Nature of the Universe 4.722ff.). "Imaginative representations" are objects of the imagination, not sensations; they are the result of effluxes from external objects blending together to form unreal objects and then entering the mind through the body. This seems to be what is meant by notions derived from composition, as explained above. For example, the idea of a centaur results from the effluxes of a man and a horse colliding and forming a being which is part horse and part man. Because it is much flimsier than those that enter the sense organs, this type of efflux given off by external objects leaves the sense organs unaffected, by-passing them altogether; rather they penetrate the body, and set the mind in motion, which explains why a person does not "see" objects of the imagination, but merely thinks or imagines them. (According to Lucretius, some of these films are produced spontaneously in the air itself, not originating in external objects.) The fact that the mind is able to create objects of the imagination at will is explained as the result of the mind's simply looking for certain collections of atoms and finding them; all possible combinations of atoms are to be found at any given time, and can be sensed if the mind looks for them.
According to Epicurus, the second criterion of truth is preconceptions (tas prolępseis). In addition to sensations and objects of the imagination, there exist abstractions from sensations, what Epicurus calls preconceptions. Diogenes explains, "By preconception they mean a sort of apprehension or right opinion or notion, or universal idea stored in the mind; that is, a recollection of an external object often presented" (Lives 10.33). Memory serves as a repository of sensations; this capacity for storage and retrieval of sensations allows the mind to form general ideas by which it then classifies new sensations; the mind has a "preconception" of the individual object that it is perceiving by means of having and comparing many previous similar perceptions. For example, the general idea or preconception of a horse or a cow arises from the abstraction of a general idea or essence of "horse" and "cow" from many remembered sensations of individual objects that later become known as horses and cows. Because preconceptions derive from sensations, Epicurus insists that they are always clear and serve as a criterion or determinant of truth. These preconceptions, however, are not Ideas in the Platonic sense, but simply abstractions originating in many perceptions; Epicurus is a nominalist in this regard, since the mind could abstract in different ways for different purposes. Whether Epicurus believes that there is a necessity to the preconceptions that actually arise from perceptions or whether these are arbitrary and could be replaced by another set of preconceptions is not clear.
Since neither sensations nor preconceptions can be "wrong" in themselves, Epicurus explains the origin of error as wrong judgment. Although it is not completely clear, it seems that error results from a misinterpretation of a sensation. Epicurus says,
Error would not have occurred, if we had not experienced some other movement in ourselves, conjoined with, but distinct from, the perception of what is presented. And from this movement, if it be not confirmed or be contradicted, falsehood results; while, if it be confirmed or not contradicted, truth results. (Lives 10.51)This "other movement" seems to be the judgment that decides whether a sensation is an instance of a preconception or not. A person who makes a judgment—in the sense of subsuming a sensation under a preconception—must "confirm" this judgment by showing that the external object perceived actually has the properties belonging to the preconception. Neither sensations nor preconceptions are false, but only the connection of the two in wrong judgment, which he calls opinion (doxa) or assumption (hupolępsis). In some cases, however, no such direct confirmation of judgment is possible, because the external objects (and their properties) are hypothetical, being inferred from sensations, i.e., directly observable external objects. (In this case both the individual external objects and the preconceptions are hypothetical.) When it creates hypotheses, the mind is making a judgment based on sensations; so long as it is not "contradicted" by sensations, then the judgment is true or, at least, true enough. (See also Diogenes' own summary in Lives 10.34). Lucretius provides further insight in the Epicurean explanation of error in his discussion of the nature of vision. He writes,
"Other cases of the sort wondrously many do we see, which all seek, so to say, to injure faith in sense—in vain, because the largest part of these deceives through mere opinions of the mind, which we do add ourselves, feigning to see what by the senses are not seen at all. For nothing is harder than to separate plain facts from dubious, which the mind forthwith adds by itself (On the Nature of the Universe 4.462-68)
According to Lucretius, visual deception results not from false sensations, since there can be no such thing, but from the "opinions of the mind," which "we"—or the mind—add to sensation.
The third criterion of truth is the feelings, of which there are two: pleasure (hedonę) and pain (algedona); all other affective states are manifestations of these two fundamental types of feelings. These two feelings are relevant in particular to the human faculty of the will. Diogenes says, "They affirm that there are two states of feeling, pleasure and pain, which arise in every animate being, and that the one is favorable and the other hostile to that being, and by their means choice and avoidance are determined" (Lives 10.34). Pleasure and pain are associated with sensations and preconceptions and are the irrefutable means by which an animate being determines what to choose or avoid. This means that pleasure and pain are criteria of truth, because it is impossible to deny that what is felt as pleasurable is not or, conversely, that what is felt as painful is not.
Diogenes explains that Epicureans distinguish two types of inquiry: "the one concerned with things (pragmata), the other with nothing but words ("sounds") (psilę hę phonę)" (Lives 10.34). A person can inquire after things or about empty words; obviously the former is true inquiry, whereas the latter is spurious. In his Letter to Herodotus, Epicurus writes,
In the first place, Herodotus, you must understand what it is that words denote, in order that by reference to this we may be in a position to test opinions, inquiries, or problems, so that our proofs may not run on untested ad infinitum, nor the terms we use be empty of meaning. For the primary signification of every term employed must be clearly seen, and ought to need no proving; this being necessary, if we are to have something to which the point at issue or the problem or the opinion before us can be referred. (Lives 10.37-38)
It is possible for words to be mere sounds, having no signification. From what he says elsewhere, Epicurus holds that, for it to have meaning, a word must be connected to sensations, preconceptions, which derive from sensations, and/or feelings; otherwise only confusion will ensue when one tries "to test opinions, inquiries, or problems." Epicurus insists that, "For the primary signification (to prôton ennoęma) of every term employed must be clearly seen, and ought to need no proving" (Lives 10.38). Every word must clearly point to some sensation, preconception or feeling; there is no need to prove that the word must point to one of these, since these are the starting point of language.
Epicurus has an ulterior motive in the formulation of his physical theories. He tells Pythocles,
"For in the study of nature we must not conform to empty assumptions and arbitrary laws, but follow the promptings of the facts; for our life has no need now of unreason and false opinion; our one need is untroubled existence. All things go on uninterruptedly, if all be explained by the method of plurality of causes in conformity with the facts, so soon as we duly understand what may be plausibly alleged respecting them. But when we pick and choose among them, rejecting one equally consistent with the phenomena, we clearly fall away from the study of nature altogether and tumble into myth." (Lives, 10.85)All explanation serves the purpose of producing an "untroubled existence." Knowing why something is so serves to rid the mind of doubt and fear. To explain nature requires a conformity of all theory to the facts, by which he means empirical data. In some cases, the empirical data may require the acceptance of more than one possible explanation, what Epicurus calls "the method of plurality of causes in conformity with the facts" (panton kata pleonachon tropon ekkathaipomenon). It is a human tendency to want only one explanation of the facts, but in some cases the state of the evidence requires allowing for more than one possible explanation. To choose arbitrarily one of several equally possible explanations is to move from the study of nature to myth, which is likewise characterized by arbitrary explanation. So, in his Letter to Pythocles, in which he undertakes to explain celestial phenomena, Epicurus often puts forward more than one explanation for a particular phenomenon. For example, in his discussion of the cause of the waning and waxing of the moon, he notes, "But one must not be so much in love with the explanation by a single way as wrongly to reject all the others from ignorance of what can, and what cannot, be within human knowledge, and consequent longing to discover the undiscoverable" (Lives, 10.94; see also 10.98, 100-101, 114).
Epicurus consistently rejects all supernatural or mythical explanations, not only because he thinks that these are wrong, but also because they do not produce an untroubled existence (see Lives, 10.115, 116). (In fact, it seems that for Epicurus a sure indicator of an erroneous explanation is that the fact it does not secure a happy life, free from anxiety.) Concerning the explanation of lightning, he says, "And there are several other ways in which thunderbolts may possibly be produced. Exclusion of myth is the sole condition necessary; and it will be excluded, if one properly attends to the facts and hence draws inferences to interpret what is obscure" (Lives, 10.104). No doubt, he has in mind the explanation of lightning as a divine means of retribution; by explaining lightning naturalistically, one frees oneself from the fear of being the object of Zeus' sometimes arbitrary wrath.
Lucretius composed the following panegyric for Epicurus:
Whilst human kind throughout the lands lay miserably crushed before all eyes beneath Religion- who would show her head along the region skies, glowering on mortals with her hideous face- a Greek it was who first opposing dared raise mortal eyes that terror to withstand, whom nor the fame of Gods nor lightning's stroke nor threatening thunder of the ominous sky abashed; but rather chafed to angry zest his dauntless heart to be the first to rend the crossbars at the gates of Nature old. And thus his will and hardy wisdom won; and forward thus he fared afar, beyond the flaming ramparts of the world, until he wandered the unmeasurable All. Whence he to us, a conqueror, reports what things can rise to being, what cannot, And by what law to each its scope prescribed, its boundary stone that clings so deep in Time. Wherefore Religion now is under foot, and us his victory now exalts to heaven (On the Nature of the Universe 1.55-80)Epicurus is praised for being the first to reject the religious and superstitious interpretation of nature; resisting the force of tradition, he undertook to discover the true explanations of natural phenomena.
Although he allows for the possibility of multiple explanations of natural phenomena, Epicurus believes that there are some physical explanations that are certain; these form the basis of his model of the cosmos, his physical theory. The two most useful sources for a reconstruction of Epicurean physics are Epicurus' Letter to Herodotus and On the Nature of the Universe by Lucretius, who sets forth numerous propositions explaining Epicurean physics. As already indicated, Epicurus is heavily influenced by Democritus for his physical theories. In Book One of On the Nature of the Universe, Lucretius outlines the theoretical foundation for Epicurean physics. He asserts that nothing can be created out of nothing, even by the gods; rather everything comes from a conglomeration of atoms in an ordered way. A corollary to this is that "Nature resolves everything into its component atoms and never reduces anything to nothing."
In his Letter to Herodotus, Epicurus asserts that atoms exist, and, as the fundamental building blocks of reality, do not change, unlike the things composed of atoms. The reason that Epicurus knows with certainty that atoms exist is that Reason demands it, since otherwise there could no change, which was not included as part of his canon, or epistemology, as a criterion of truth. Ultimately that which changes requires component parts that are unchanging. In other words, it is axiomatic that for there to be any change there must be something that remains unchanged, and these are the atoms. He explains this insight as follows, "For every quality changes, but the atoms do not change, since, when the composite bodies are dissolved, there must be a permanent something, solid and indissoluble, left behind, which makes change possible: not changes into or from the non-existent, but often through differences of arrangement, and sometimes through additions and subtractions of the atoms" (Lives 10.54). It is not immediately obvious, however, how this axiom would be classifed according to the Epicurean canonic, or epistemology, since it seems to be an a priori truth, a truth of Reason (known before experience as necessary and eternal), and not derived from sensation, preconception or feeling. The atoms are solid and indestructible, whereas their compounds are mixtures of atoms and vacuity, and are, thereby, destructible, in the sense of being liable to decomposition. What is normally called perishing or destruction, therefore, is actually the disconnecting of indestructible atoms. In addition to atoms and their composites, Epicurus assumes empty space or the void as the other principle of nature: what exists is bodies, composed of atoms, in empty space; these two realities are the principles of explanation of everything. In his On the Nature of the Universe, Lucretius explicitly introduces the idea of empty space or the void as the other principle of nature: what exists is bodies, composed of atoms, in empty space; these two realities are the principles of explanation of everything (Book One). Epicurus also accepts the common sense understanding of time: "We must chiefly reflect upon that to which we attach this peculiar character of time, and by which we measure it. No further proof is required" (Lives 10.72-73)
Epicurus also reasons that atoms, although invisible, must be of different sizes, for the diversity of visible things requires that their component parts be equally diverse. This is an argument from an effect to its sufficient cause. He says, "But differences of size (megethos) must be admitted; for this addition renders the facts of feeling and sensation easier of explanation" (Lives 10.55). He adds, "On the analogy of things within our experience we have declared that the atom has size; and this, small as it is, we have merely reproduced on a larger scale (Lives 10.58-59). Since the composite things that we perceive have size, the conclusion follows by analogy that the imperceptible, indivisible parts that make up composite objects have size also. Necessarily, Epicurus rejects the idea of the infinite divisibility of matter, since atoms are not divisible, which further leads to the conclusion that anything can only have a finite number of atoms: "Not only must we reject as impossible subdivision ad infinitum into smaller and smaller parts...but in dealing with finite things we must reject as impossible the progression ad infinitum by less and less increments" (Lives 10.56). All atoms travel through the void, or empty space, at the same velocity, if unobstructed (Lives 5.61).
Atoms, imperceptible to the human sense organs, are indivisible and therefore indestructible units of matter that have, in addition to size, shape and weight (schęmatos kai barous kai megethos). All other perceived qualities, such as color or taste result from atoms affecting human sense organs, and can be called secondary or derivative. He writes, "We must hold that the atoms in fact possess none of the qualities belonging to things which come under our observation, except shape, weight, and size, and the properties necessarily conjoined with shape (10.54). He distinguishes between the permanent qualities of a composite thing, which correspond to the permanent qualities of its atoms, from that thing's accidents, which are its impermanent and variable qualities and do not exist apart from bodies and are not parts of bodies (10.69-70). He explains,
Again, qualities often attach to bodies without being permanent concomitants. They are not to be classed among invisible entities nor are they incorporeal. Hence, using the term 'accidents'in the commonest sense, we say plainly that 'accidents' have not the nature of the whole thing to which they belong, and to which, conceiving it as a whole, we give the name of body, nor that of the permanent properties without which body cannot be thought of.
It is not explained, however, why it is not possible to argue by analogy that the atoms must have the secondary or derivative qualities; perhaps Epicurus does not include them as qualities of atoms because they are more variable than shape, weight and size. In Book Two of On the Nature of the Universe, Lucretius discusses atoms and their properties in more detail. Atoms not only differ from one another in size, but also in shape; this explains the diversity of things in experience. The different types of atoms are finite, whereas the number of atoms is infinite, so that the number of each different type of atom must also be infinite. It also follows that an infinite number of atoms must exist in the infinite void or empty space. Lucretius also affirms that no visible thing is composed of the same type of atom, but all composite things are compoesed of different types of atoms. In addition, Epicurus rejects the Platonic notion that the qualities of a composite thing exists independently of it. He writes that objects "all have their own characteristic modes of being perceived and distinguished, but always along with the whole body in which they inhere and never in separation from it" (10.69). There are two types material objects in the universe: atoms and compounds made of atoms. There are no Ideas that exist independently of atoms and their compounds, in which the latter participate, as Platonists believe.
Atoms are in perpetual motion through the universe moving downward by virtue of their own weight; the whole process of generation and destruction, i.e., the creation of worlds (see Letter to Pythocles, in Lives, 10.88-89), begins when these atoms swerve spontaneously i.e., without cause, from their straight course through the void, and collide with other atoms, thus becoming entangled together and making composite things. Each world is said to be cut off from the infinite (apoton) and there is an infinite number of worlds. The fact that the atoms swerve without cause is the basis for the freedom of the will, which philosophers of other schools sometimes claim is an Epicurean deus ex machina designed to avoid philosophical determinism that would follow from atomism (Cicero, The Nature of the Gods, 1.68-70). When they become disentangled from other atoms at the decomposition of a composite thing, the atoms continue on their way through the infinite void; new atoms, however, continually arrive at any point in infinite space, which then combine to form compounds. According to Lucretius, there are three causes of motion:
The fact that there is regularity in our experience is an indication that there are principles for the organization of atoms, or what the Epicureans call "seeds"; in other words, things arise according to some specific necessity (Lucretius, On the Nature of the Universe, 2.674-740). Certain atoms are brought together in a certain arrangement and are maintained as the organism grows; existing things give rise to offspring by causing another entity to arise like itself in accordance with the same principles of organization of atoms or "seeds." Were this not so, all sorts of combinations would result, so that there would be no uniformity in the natural world. What exactly these seeds are, however, is not explained; they could not be something like Platonic Ideas, since such immaterial entities cannot exist in an Epicurean universe. Their nature remains a mystery.
For an Epicurean, the human being is composed of a body and a soul or spirit; both of these, not surprisingly, are compounds of atoms. The body and its various parts are compounds of differently sized and shaped atoms; upon death the atoms become disentangled from one another and continue on their way through the void. The soul or spirit is also composed of atoms, but of much finer types than those that constitute the body. Epicurus says,
We must recognize generally that the soul is a corporeal thing, composed of fine particles, dispersed all over the frame, most nearly resembling wind with an admixture of heat, in some respects like wind, in others like heat. But, again, there is the third part which exceeds the other two in the fineness of its particles and thereby keeps in closer touch with the rest of the frame. (Diogenes, Lives, 10.63)
The soul is compounded of atoms similar to the atoms responsible for wind and heat: for this reason "besouled" bodies have breathe (wind) and are warm (heat). There is, however, a third type of atom that is part of the soul, finer than the other two: it is that which is responsible for sensation. These atoms are affected and set in motion by the thin replicas (eidola) or films composed of atoms that enter the body through the five senses. The soul consisting of these three types of atoms is diffused throughout the entire body. Epicurus rejects the commonly-accepted idea of the incorporeity of the soul as nonsensical, since only space can be said to be incorporeal: "But it is impossible to conceive anything that is incorporeal as self-existent except empty space. And empty space cannot itself either act or be acted upon, but simply allows body to move through it. Hence those who call soul incorporeal speak foolishly (Lives, 10.67).
Lucretius has a more elaborate anthropology. According to him, the mind or spirit, also called the vital spirit, is one substance and is diffused throughout the body, although the mind or intellect, as part of the vital spirit, resides predominantly in the mid-region of the breast (see Diogenes' addition in Lives, 10.86). (Lucretius is somewhat careless in his terminology.) There are proportionately fewer mind or spirit atoms in the body than there are body atoms. This substance known as mind or spirit is composed of four types of atoms: warmth, wind, air and an unnamed type; the unnamed is the smallest and the smoothest and most easily and quickly affected by other atoms, i.e. those films being given off by external objects (perception), after which the motion is passed onto the other atoms constituting the mind or intellect. The other three parts of the soul exist in different proportions in each human being, and determine his basic disposition: warmth = angry; wind = fear; air = calmness (On the Nature of the Universe, 3.93ff.).
With the dissolution of the body at death comes the dissolution of the mind or spirit; sentience or consciousness is lost when the atoms composing the soul are scattered and no longer able to move in concert with the body in such a way as to produce sentience. Epicurus writes, "For we cannot think of it as sentient, except it be in this composite whole and moving with these movements; nor can we so think of it when the sheaths which enclose and surround it are not the same as those in which the soul is now located and in which it performs these movements" (Lives, 10.66). In the confines of the body, the mind or spirit moves in harmony with the body; this movement is sentience, for which reason it is an emergent property. Epicurus seems to mean that the type of atom responsible for sentience is actually sentient only when contained within the body and affected by the body and the thin replicas (eidola) of objects entering the body through the sense organs. When the atoms of the mind or spirit are no longer contained by the body, they lose their collective movement caused by the body, which explains why death brings unconsciousness. Since they can no longer be affected sensibly, the soul atoms become insentient. Exactly why these atoms responsible for sentience require containment in a body in order to be actually sentient, however, is not explained further. (Perhaps one might compare these atoms to brain cells that require connections to other brain cells in order to function as part of a brain.) So it follows that there is no possibility of immortality for the human being. According to Lucretius, there are only three eternal things:
Then, again, whatever abides eternal must indeed either repel all strokes, because 'tis made of solid body, and permit no entrance of anything with power to sunder from within the parts compact- as are those seeds of stuff whose nature we've exhibited before; or else be able to endure through time for this: because they are from blows exempt, as is the void, the which abides untouched, unsmit by any stroke; or else because there is no room around, whereto things can, as 'twere, depart in dissolution all,- even as the sum of sums eternal is, without or place beyond whereto things may asunder fly, or bodies which can smite, and thus dissolve them by the blows of might. (On the Nature of the Universe, 3.810-20)Atoms are eternal because they are impenetrably solid and cannot be destroyed, and the void is eternal since it remains unaffected by any impact that it may receive. Finally, the whole universe is eternal because there is nowhere beyond the universe to where its matter can escape, which means that it can never disintegrate. The human spirit or mind, however, is not classified among eternal things, since it is composite and will decompose.
An Epicurean does not view death as a problem. Epicurus writes in his Ta Kuria, "Death is nothing to us; for the body, when it has been resolved into its elements, has no feeling, and that which has no feeling is nothing to us" (Lives, 10.139). Since there can be no pain when there is no consciousness, and since pain is the only thing to be feared, death is not to be feared since it is the cessation of consciousness. In other words, death is nothing to a sentient being, because it is a lack of sentience. Likewise, Lucretius points out that mortality is the lot of human beings, and is not something to mourn, since death is only insentience (On the Nature of the Universe, 3.827-40). Epicurus offers this sage advice concerning how one ought to view death:
Accustom yourself to believe that death is nothing to us, for good and evil imply awareness, and death is the privation of all awareness; therefore a right understanding that death is nothing to us makes the mortality of life enjoyable, not by adding to life an unlimited time, but by taking away the yearning after immortality. For life has no terror; for those who thoroughly apprehend that there are no terrors for them in ceasing to live. Foolish, therefore, is the person who says that he fears death, not because it will pain when it comes, but because it pains in the prospect. Whatever causes no annoyance when it is present, causes only a groundless pain in the expectation. Death, therefore, the most awful of evils, is nothing to us, seeing that, when we are, death is not come, and, when death is come, we are not. It is nothing, then, either to the living or to the dead, for with the living it is not and the dead exist no longer. But in the world, at one time people shun death as the greatest of all evils, and at another time choose it as a respite from the evils in life. The wise person does not deprecate life nor does he fear the cessation of life. The thought of life is no offense to him, nor is the cessation of life regarded as an evil. And even as people choose of food not merely and simply the larger portion, but the more pleasant, so the wise seek to enjoy the time which is most pleasant and not merely that which is longest. And he who admonishes the young to live well and the old to make a good end speaks foolishly, not merely because of the desirability of life, but because the same exercise at once teaches to live well and to die well. Much worse is he who says that it were good not to be born, but when once one is born to pass with all speed through the gates of Hades. For if he truly believes this, why does he not depart from life? It were easy for him to do so, if once he were firmly convinced. If he speaks only in mockery, his words are foolishness, for those who hear believe him not. (Lives,10.124-27)Since in death there is no awareness of being dead, death is nothing to the living. There is no point to worrying about something whose presence causes no pain. It would seem that Epicurus does not believe that human beings desire to remain in existence forever, so that the prospect of non-existence causes pain to the living. Thus, the wise man will not allow death to disturb his happiness while living. The benefit of mortality for the living is the cessation of the yearning and striving for immorality, which invariably produces fear of post-mortem punishment.
As already indicated, Epicurean philosophers believe in the freedom of the will; the basis of this is the fact that atoms spontaneously swerve from their course through the void. This spontaneity on the atomic level carries over into and permeates all the atomic compounds, especially human beings. Thus, it is no surprise to find Epicurus, in his Letter to Menoeceus, rejecting the concept of Destiny (heimarmenê):
Destiny which some introduce as sovereign over all things, he laughs to scorn, affirming rather that some things happen of necessity, others by chance, others through our own agency. For he sees that necessity destroys responsibility and that chance or fortune is inconstant; whereas our own actions are free, and it is to them that praise and blame naturally attach. It were better, indeed, to accept the legends of the gods than to bow beneath destiny which the natural philosophers have imposed. (Lives, 10.133).
The Epicurean philosopher knows that responsibility implies human freedom, so that the Stoic concept of Destiny must be wrong.
Epicurus does not deny the existence of the divine. In fact, according to (the fictional) Velleius in Cicero's On the Nature of the Gods, who is an Epicurean philosopher, belief in the gods among human beings is universal and so has the status of a "prolêpsis" ("a certain idea of a thing formed by the mind beforehand"), a general and de facto innate idea (1.43). It is also universally held that the gods have a human appearance. This conclusion is based on two undisputed facts. First, no group of human beings has ever conceived the gods otherwise. Second, it is only fitting that the gods, perfect beings, be beautiful and there is no form more beautiful than the human form (1.46-48). It must be stressed that, according to Epicurus, the bodies of the gods are only analogous to human bodies ("quasi corpus"): "It must be admitted that the gods have the outward aspect of man, though this is not body, but quasi-body, and does not contain blood, but quasi-blood" (1.49). Epicurus denies, however, the relevance of the gods to human beings; one could say that Epicureanism is a form of practical atheism. Epicurus writes in Letter to Menoeceus:
Those things which without ceasing I have declared to you, those do, and exercise yourself in those, holding them to be the elements of right life. First believe that God is a living being immortal and happy, according to the notion of a god indicated by the common sense of humankind; and so believing, you shall not affirm of him anything that is foreign to his immortality or that does not agree with his blessedness, but you shall believe about him whatever may uphold both his blessedness and immortality. For truly there are gods, and knowledge of them is evident; but they are not such as the multitude believe, seeing that people do not steadfastly maintain the notions they form respecting them. Not the person who denies the gods worshipped by the multitude, but he who affirms of the gods what the multitude believes about them is truly impious. For the utterances of the multitude about the gods are not true preconceptions but false assumptions; hence it is that the greatest evils happen to the wicked and the greatest blessings happen to the good from the hand of the gods, seeing that they are always favorable to their own good qualities and take pleasure in people like to themselves, but reject as alien whatever is not of their kind. (Lives, 10.123)
According to the above quotation, Epicurus advises belief in both God and the gods, but rejects the popular notion that human blessedness and misery are in the hand of the gods. According to him, the gods do not reward the good and punish the wicked. Such a notion is a misconception of the ignorant masses: "For the utterances of the multitude about the gods are not true preconceptions but false assumptions; hence it is that the greatest evils happen to the wicked and the greatest blessings happen to the good from the hand of the gods, seeing that they are always favourable to their own good qualities and take pleasure in men like unto themselves, but reject as alien whatever is not of their kind" (10.124). The gods, like everything else, are composed of atoms, but obviously of a different type than human beings. It is a recurrent theme in Epicurean philosophy that human beings wrongly interpret natural phenomena as the activities of gods. As already indicated, the goal of Epicurus' physical investigation is to prove that nature requires no such supernatural causal causes; everything can be explained in naturalistic terms. When superstition is eliminated human beings need no longer fear that they may become the object of a god's irrational wrath or malevolence. Lucretius explains that the gods neither made the cosmos, are involved in the management of it, nor care anything about the affairs of human beings (On the Nature of the Universe, 2.167-83, 1090-1104; 5.91-415). Lucretius points out that the cosmos could not have been created by the gods since it is so imperfect, and, therefore, unworthy of divine craftsmanship. The gods are composed of very flimsy atoms, so that they are ethereal, scarcely even perceptible by the mind; they cannot be touched or touch. It follows that they live somewhere adapted to their nature, which means that they do not dwell anywhere near human beings (On the Nature of the Universe, 5.136-55).
It is a recurrent theme in Epicurean philosophy that human beings wrongly interpret natural phenomena as the activities of gods. As already indicated, the goal of Epicurus' physical investigation is to prove that nature requires no such supernatural causal factors; everything can be explained in naturalistic terms. When superstition is eliminated human beings need no longer fear that they may become the object of a god's irrational wrath or malevolence.
In his Letter to Menoeceus, Epicurus provides an outline of his ethics. A more complete summary of Epicurean ethics, however, is found in Cicero's De finibus bonorum et malorum (1.9-21). As stated earlier, feeling was considered a criterion of truth, and there were two basic feelings: pleasure and pain. Whatever is pleasurable is good and whatever is painful is bad. This is taken as self-evident truth, for which no argumentation is needed; it is based in human nature. Epicurus writes, "Pleasure is our first and kindred good. It is the starting-point of every choice and of every aversion, and to it we come back, inasmuch as we make feeling the rule by which to judge of every good thing" (Lives, 10.129). Pleasure (hedonê) is the first good, because any other "good," that which is determined to be worthy of pursuit, is good because it leads to pleasure; conversely, whatever is to be avoided is not pleasurable. Pleasure is a "kindred" (suggênikon) good because it is congenital to or inborn in every sentient being, so that no one can deny that pleasure is the first good. Pleasure is the end (telos) of all intentional behavior and is therefore the only human good. Cicero elaborates on the primacy of pleasure:
We are inquiring, then, what is the final and ultimate Good, which as all philosophers are agreed must be of such a nature as to be the End to which all other things are means, while it is not itself a means to anything else. This Epicurus finds in pleasure; pleasure he holds to be the Chief Good, pain the Chief Evil. This he sets out to prove as follows: Every animal, as soon as it is born, seeks for pleasure, and delights in it as the Chief Good, while it recoils from pain as the Chief Evil, and so far as possible avoids it.This it does as long as it remains unperverted, at the prompting of Nature's own unbiased and honest verdict. Hence Epicurus refuses to admit any necessity for argument or discussion to prove that pleasure is desirable and pain to be avoided. These facts, be thinks, are perceived by the senses, as that fire is hot, snow white, honey sweet, none of which things need be proved by elaborate argument: it is enough merely to draw attention to them. (For there is a difference, he holds, between formal syllogistic proof of a thing and a mere notice or reminder: the former is the method for discovering abstruse and recondite truths, the latter for indicating facts that are obvious and evident.) Strip mankind of sensation, and nothing remains; it follows that Nature herself is the judge of that which is in accordance with or contrary to nature. What does Nature perceive or what does she judge of, beside pleasure and pain, to guide her actions of desire and of avoidance? (De finibus bonorum et malorum, 1.9)Cicero explains that, for Epicurus, the chief or first good is pleasure and pain is the chief or first evil. This needs no proof, since one cannot contradict Nature. It follows that Epicurean ethics is an utilitarian or consequentialist eudaimonism, since the end (pleasure) justifies the means: whatever produces or maintains a sentient being in a state of pleasure is good and whatever does not is evil.
It must be stressed that Epicurus defines pleasure negatively, not as the presence of certain sensations, but by their absence. He says, "By pleasure we mean the absence of pain in the body and of trouble in the soul" (Lives, 10.131-32). Pleasure is not a sensuality, the stimulation of the senses; rather it is the absence of bodily pain and mental disturbance. Epicurus explains,
We must also reflect that of desires some are natural, others are groundless; and that of the natural some are necessary as well as natural, and some natural only. And of the necessary desires some are necessary if we are to be happy, some if the body is to be rid of uneasiness, some if we are even to live. He who has a clear and certain understanding of these things will direct every preference and aversion toward securing health of body and tranquility of mind, seeing that this is the sum and end of a happy life. (Lives, 10.128)The fulfillment of unnatural and even unnecessary desires is to be avoided, because the Epicurean goal of a "happy life" (makarios zan) is secured by "health of body" and "tranquility of mind" (ataraxia). Only those things the absence of which will lead to bodily pain and mental disturbance are pursued. Cicero explains that, for Epicurus, it is the complete removal of pain that causes pleasure (De finibus bonorum et malorum, 1.11). This leads Epicurus to value independence (autakreia) as a derivative good, since it leads to pleasure defined negatively as the absence of physical and mental pain:
Again, we regard independence of outward things as a great good, not so as in all cases to use little, but so as to be contented with little if we have not much, being honestly persuaded that they have the sweetest enjoyment of luxury who stand least in need of it, and that whatever is natural is easily procured and only the vain and worthless hard to win. Plain fare gives as much pleasure as a costly diet, when once the pain of want has been removed, while bread and water confer the highest possible pleasure when they are brought to hungry lips. To habituate one's self, therefore, to simple and inexpensive diet supplies all that is needful for health, and enables a person to meet the necessary requirements of life without shrinking, and it places us in a better condition when we approach at intervals a costly fare and renders us fearless of fortune. (Lives, 10.130-31)To be a human being is to be dependent on externals in order to live happily; unfortunately, these externals are sometimes inaccessible, so that one loses one's state of tranquility of mind. The best response to the dependence on externals is to minimize it as much as possible, to reduce to a natural minimum the conditions that need to met for one's happiness. It is not that unnatural or unnecessary pleasure is wrong in itself, but only that, since its source is outside of one's control, eventually one will experience the pain of want because such objects will at times not be available. It is better not to become habituated to and dependent on this unnecessary external thing for one's happiness, since it is not natural, and therefore not truly necessary for happiness. Thus Epicurus values the virtue of moral insight (phronêsis), since this allows one to assess one's true needs for happiness; it also teaches that one cannot lead a life of pleasure without honor and justice (Lives, 10.132).
As already indicated, human mortality is productive of tranquility of mind; if death is loss of consciousness through the dissolution of the body and the soul into its component atoms, then there is nothing to fear in death. Death is nothing to us, because the perception of good and evil requires sentience and death is the privation of sentience. This inight liberates a person to enjoy finite existence without the distraction of the yearning for immortality and fear of possible suffering in the next life. Likewise, the fact that the gods have no interest in human affairs frees one from the fear of the gods in this life.