[Image from Common Sense Science]
Parmenides of Elea changed the course of early Greek philosophy. His philosophy not only shifted the line of inquiry found in previous accounts (most notably in the Milesians Thales, Anaximander, and Anaximenes) from cosmology to ontology; the ontology he developed also defined all succeeding accounts as the standard to which they, in some way or other, had to adhere to, even if the successors wanted to do something else to Parmenides’ account or downright contested it. This is the way in which Parmenides (followed by Zeno and Melissus, also from Elea) set out the so-called “Eleatic challenge,” which all those that succeeded him obviously took (or had to take) very seriously.
In his groundbreaking philosophy, Parmenides established that there is only one thing that there is (in reality) which can be spoken of and thought (McKirahan 163). This being, as it has come to be called, is ungenerated and imperishable, has a timeless existence, is undivided and continuous, and is motionless (166-70). These characteristics establish the spatiotemporal invariance and all-encompassing nature of this being. As such, it is all that there is, i.e. it is what there is.
What does not fall under being, what does not measure up to it, what is contrary to it—i.e. nothing—is not. Nothing is thus incoherent with being. As such, nothing is impossible to be spoken of and thought. Since, to Parmenides, speech and thought are not distinguished from reality, it follows that nothing does not exist. In a very real sense, then, nothing is nothing. Thus nothing—failing to stand up to the demands of being, failing to be, in fact, being the diametrical opposite of being—does not—cannot—appear in the ontological picture. Thus Parmenides establishes being—this one being—being and only being—as ontology, invalidating everything else that is not, including everything that in some way or another is contaminated with nothing. Thus Parmenides gave birth to ontology.
In Presocratic thought, there are three main responses to this Parmenidean ontology. These were the ontologies developed by Anaxagoras, Empedocles, and the Atomists Leucippus and Democritus. All three schools seem to have one purpose in mind: while starting from or taking into consideration Parmenides’ ontology, they nonetheless wanted to take account of the phenomenal world of diversity and change, which Parmenides’ ontology—admitting only being—definitively foreclosed as something incoherent, contaminated (with nothing), and thereby nonexistent.
The way in which the three lines of thought did this, however, differed. As C.C.W. Taylor explains in The Cambridge Companion to Early Greek Philosophy:
For Anaxagoras the primary things were observable stuffs and properties, and for Empedocles they were the elements, earth, air, fire, and water: for both, the primary processes were mixing and separation of those primary things. By contrast, for the atomists the primary things were not properties or stuffs but physical individuals, and the primary processes were not mixing and separation but the formation and dissolution of aggregates of those individuals. Again, the basic individuals were unobservable, in contrast with the observable stuffs of Anaxagoras and the observable elements of Empedocles. Consequently, their properties could not be observed but had to be assigned to those individuals by theory. (182)
Anaxagoras, Empedocles, and the Atomists thus posited a world of “primary things,” a “primary” or “fundamental world” if you will, that complies with the demands of the Eleatic ontology. The brilliant move they made, however, was to posit a secondary phenomenal world that, in some way or other, arises out of the primary world, thus technically not violating Parmenides’ ontology (which their primary worlds adhered to) while at the same time legitimating the things that we experience, the world in which we live (which they legitimated by making it secondary). (Technically, Anaxagoras posited more than just two “worlds” or “levels,” but for simplicity’s sake, he is included here. Needless to say, his account is more complex than is able to be fitted in the framework presented here.)
Three things, however, make the Atomist account stand out. First, unlike in Anaxagoras and Empedocles, the primary elements posited by the Atomists are, as Taylor points out, unobservable. There is thus a sense in which the Atomists have more leeway—are freer—than either Anaxagoras and Empedocles in what they make of those primary elements, thus enabling them to at the same time move the furthest away from Parmenides (since no one can see and verify whether these primary elements in fact comply with Parmenides’ characterization of primary being) while at the same time claiming that they stay closest to him (again, since no one can verify; everyone has to rely on what the Atomists say about their primary elements).
Secondly, due to this unobservable nature of the Atomists’ primary elements, the connection between them and the secondary phenomenal world that they form need not be apparent. Since, as noted above, the Atomists’ primary elements cannot be seen, how exactly these primary elements form and connect to the secondary phenomenal world cannot be verified by empirical evidence. As such, once again, we have to rely on what the Atomists say—i.e. to their theorization—and measure the validity and acceptability of their account purely through logic (without being burdened by the contradictions and possibly contrary evidence of empirical reality) and, in some way, with the trust we’ve already given them (by hearing them out).
More importantly, due to its unobservable and theoretical nature, the Atomist response is something that would seem to be most acceptable to Parmenides himself. Not empirical, the account does not rely on what is perceivable and apparent in the world, which, to Parmenides, is merely the world of appearance that holds no sway. If the Atomist response was empirical, Parmenides can quickly discount it as merely cosmological (like the accounts that preceded him). The Atomist account, however, like Parmenides’, is metaphysical. It thus confronts Parmenides’ ontology on its own level, responding to it directly and, one can argue, most substantially. This is the way in which the Atomists’ response to the Eleatic challenge presents the most promise.
While not intending to disparage Anaxagoras and Empedocles’ accounts, in this paper I focus on the Atomist account of reality, specifically the way that they responded to and appropriated Parmenides’ ontology. I begin by discussing in depth the Atomist ontology that results from that response, composed as it is of atoms and the void. I then discuss how atoms and the void form compounds, which, to the Atomists, is that which we experience in the phenomenal world. (This is the way in which the phenomenal world is composed of compounds, which are constituted by atoms and the void.) I then give a brief account of Atomist cosmogony, “anthropology” (account of human beings), and epistemology—accounts that are grounded in the ontology—and end by raising the question as to whether the Atomist ontology is mechanistic.
Atoms: Being multiplied
The first way in which the Atomists depart from the Parmenidean account of reality is their assertion that there are two—not one—elements that there be, two elements that are to be taken into account when constructing ontology. As Richard McKirahan recounts in Philosophy Before Socrates, Leucippus and Democritus call these two elements “what is” and “what is not,” giving them equal ontological status, i.e. asserting that they are both there, that they both exist (304). Atoms—what is—are alternately called “full, solid, compact, [. . .] being, and [t]hing,” while the void—what is not—is “empty, rare, unlimited or infinite, [. . .] not-being, nothing” (307). Atoms are also referred to as “thing,” “massy,” “body,” and, as Jonathan Barnes stresses in The Presocratic Philosophers, “being” (345). The interaction between these two elements cause/explain the world in which we live, i.e. construct and shape what there is.
Atoms are described as eternal (McKirahan 307). They are similar, then, to Parmenides’ being in not exhibiting any temporal variance. They stay the same as they are and have no beginning or end. They have no origin and did not come to be (i.e. are ungenerated) seeing as they have always been there. In addition, they will always be there (i.e. they are imperishable). They are also, like Parmenides’ being, indivisible (the word atomos literally means “uncuttable,” “unsplittable”), which is due both to the lack of void in atoms (which, as explained later, is what allows something to be interiorly affected) and their minute size (which cause them to lack parts into which they will be divided) (307).
By asserting that atoms are indivisible, the Atomists evade the contention by Zeno (one of the main followers of Parmenides) that if what there is has size (an attribute that comes with the assertion that there is a plurality of things), it would have to be unlimitedly large because it would lend itself to infinite division (184). By saying that atoms are indivisible, the Atomists are able to assert both that there are many such atoms and that (since they are indivisible) they are not unlimitedly large (310). Moreover, since they cannot be divided, every atom (relative to itself) does not change in size and shape, making them, like Parmenides’ being, spatially invariant.
The Atomists claim that atoms are “too small to be seen” (307). Each atom is thus finite (although there are infinitely many of them) (317). These small atoms, like Parmenides’ being, are “uniform in substance” and “without perceptible qualities,” but, unlike Parmenides’ being, atoms “differ [. . . from each other] in their spatial properties—size and shape,” and, more conspicuously, in being many (307). More specifically, “there are an unlimited number of atoms, with an unlimited number of shapes” (308). Size and shape are indeed perceptible qualities but by virtue of the atoms being so small, these qualities (in them)—like the atoms themselves—cannot be perceived. Moreover, attributes of size and shape are not perceptible in the way that other properties—e.g. hardness, hotness, dryness—are, which individual atoms do not have (308). Finally, “all atoms are made of the same stuff” (308). That is to say, they have a uniform composition, are composed of the same material.
Given these individual properties, it follows that “atoms are impassive [in the sense that they are] incapable of being affected or acted upon” (309). Atoms, then, are closed, self-sufficient entities experiencing (since they have no quality) no change in quality and no change in quantity (309). Thus, one atom will remain one atom, in the context of all atoms that, though differing in size and shape, are each made up of the same stuff. There is thus a sense in which each atom is complete and/or perfect in itself: full, as the Atomists describe it. Even change in the spatial properties of size and shape is prevented by the claim that atoms have no internal void (what, according to the Atomists, is the only room for change) (309). Atoms moreover “cannot cause changes in other atoms” (309). They cannot penetrate each other’s borders and as such they cannot affect each other internally (309). Finally, relative to itself, an atom, like Parmenides’ being, does not move (i.e. is motionless) (313).
It becomes apparent at this point that the Atomists are able to escape some of the constraints of the Parmenidean ontology by limiting what Parmenides says of being (e.g. that it exhibits spatiotemporal invariance, that it is motionless, that there is only one of it, etc.) to a single atom, i.e. by saying that the characteristics that Parmenides gives to being do in fact hold—but as they pertain to all atoms taken individually, i.e. as the characteristics of being pertain to an atom taken in its singularity. In other words, while atoms do in fact differ in size and shape from each other, while they do move relative to one other, while there are many such small atoms, relative to itself (if we look only at one atom, without reference to and without the context of other atoms with which it exists), an atom (the particular atom we’re looking at) does in fact have only one size, one shape, is unmoving, and is only one.
Hence the Atomists are able to comply with the demands of Parmenides’ ontology while at the same time changing it dramatically. They accomplish this double move by multiplying the number of what Parmenides refers to as being. That is to say, the Atomists make each atom a Parmenidean being—of which, unlike in Parmenides, there are infinitely many. In this way, the Atomists drastically change the picture of what there is, which is to include in it, as explained below, the (phenomenal) world.
The Void: Nothing as something, insufficient but necessary
The Atomists modify (while complying) the Parmenidean ontology further by positing the void, which, since not an atom, does not need to comply with the characteristics of Parmenides’ being at the same time that, even though corresponding to Parmenides’ not-being (or nothing), it (what is not) is given equal ontological status as what is (atoms), the Atomist version of being. As in Parmenides, there is in the Atomists no interpenetration between being and nonbeing in the sense that being cannot come from or become nonbeing (the old Eleatic argument) (Barnes 345). The Atomists thus maintain the disjunct and separation between being and nothing. Nonetheless, the Atomists do assert that there is nothing.
The Atomists are able to do this by virtue of a brilliant move. Leucippus asserts that “what is is no more than what is not, because the void is no less than body is” (McKirahan 315) (my emphases). Thus, “although in a sense there is less where there is void than where there are atoms, still, void is on a par with atoms in the relevant respect, being” (316). Contrary then to Parmenides who takes to the fullest the definition of “what is not” by concluding that what is not is, literally, not there, does not exist, and thus cannot even be spoken of or thought about and is thus left out of the ontological picture (not even considered or discussed), the Atomists assert paradoxically that what is not is there (in the ontological picture), that there is void, i.e. there is what is not.
Thus the Atomists’ void is not so much nothing taken as a totality. The void is not a metaphysical way to designate nothing pure and simple (which thus cannot be thought of, talked about, and exist, since it is nothing). The void is, rather, a noun form for the adjective empty, a noun form for a description, a state (of a place). In other words, rather than nothingness itself (as in Parmenides), the void for the Atomists is something empty, which, even though it has nothing in it, is still something. The void, in other words, is something in which there is not.
To put this back in the context of ancient atomism, the void is something in which that which is—i.e. atoms—is not. The void is thus something in which there are no atoms: something void. There are no atoms—nothing—in the void. As the Atomists claim, however, there is nonetheless the void.
The void is something because, as the Atomists put it, it is one of the two elements, i.e. the void is an element. It is, however, not something like air, which is corporeal, because for the Atomists, everything that has a body has atoms, which the void—being empty—does not have. The void is thus more like “an interval in which there is no perceptible body” (314). As Taylor describes it,
There is indeed something which separates any two nonadjacent atoms, namely an interval. But an interval is not any kind of thing: it is merely a gap, an absence of anything. So there are indeed gaps between atoms, but gaps are nothings, and when an atom moves, it moves into a gap. (183)
It is, McKirahan points out, precisely this lack (of anything there, of atoms)—which make it seem like a gap, an interval—that defines something as a void (314).
The void, however, even though analogous to a gap or an interval, is not the same as space either. Even as atoms can move through the void and even as they can be in the void (as when the void is sometimes described as a place for atoms (305) or atoms are described as “scattered in the void” (323)), both atoms and the void “occupy space and have location” (314). Space and location, then, are like neutral grounds in which both atoms and the void can be. What distinguishes atoms from the void is not the fact that atoms can occupy or leave the void. The void is not simply a space. Rather, both atoms and the void occupy space in an equally ontological way. That is to say, both atoms and the void are capable of being present, being there in a space, in an equally true way. What distinguishes atoms and the void from each other is thus not what distinguishes an occupant from the space being occupied, but rather a simple fact of presence (in space): “where there is void there are no atoms, and where there are atoms there is no void” (315). In both cases, a neutral space separate and different from both atoms and the void is implied.
Even as they have equal ontological status, atoms in the Atomists’ account have/are more than the void. In other words, even as they are equally present, equally there, atoms have more in them than the void, which is empty. Atoms and the void thus have equal ontological status but unequal contents. Similarly, atoms seemingly play a larger and more active role in the Atomist ontology than the void. In fact, it seems as though the void was posited so as to serve certain functions for atoms, to enable atoms to be as they are and do their work. Although, then, atoms and the void are both infinite, they are in different senses: atoms are, as Barnes puts it, (although finite individually) “unlimited in quantity” while the void is merely “unlimited in magnitude,” that magnitude being empty (of any bodily content) (343).
The void fulfills two main functions (for atoms). First, the void serves as a kind of border for the different atoms. This is made possible by the difference in nature between atoms and the void. Even more devoid of property than atoms, “the void per se lacks even the spatial properties of atoms. It has no shape or size of its own (aside from its infinite amount)” (McKirahan 317). This void, something different from each and every atom, surrounds all atoms. Thus, each atom is enabled—by virtue of the surrounding void different from it—to delineate borders, to keep itself apart from that border and hence from other atoms. This “makes possible and preserves the uniqueness and identity” of each atom, especially as “atoms are identified only by their spatial extension” (i.e. their size, shape, and location) (313).
From the void’s separation of atoms follows that “atoms [at least initially or until they move] are never in contact with one another” (313). This coheres with the fact that, due to their minute size, atoms have no parts. If atoms touched each other, the touching would presuppose parts being touched. Otherwise, atoms would have to touch each other in their entirety, which would make them collapse into each other, which would destroy the crucial distinction that the Atomists maintain against Parmenides: namely, the fact that atoms are infinitely many. Key to holding this distinction, as explained above, is the presence (the equal ontological status) of the void.
The void performs a second function: it enables atoms to move (although it must be remembered that in relation to itself, each atom does not move) by providing an empty space in which they can move, a new space in which they can occupy, pushing out what has no body (313). This implies that what has body, an atom, can easily take over the space of that which has no body, the void, in a way not necessarily possible to do to something that also has a body, i.e. to another atom. The void in this way only temporarily occupies space that the atoms can then move through or into. Movement for the Atomists is thus possible only as a change of occupancy (into a space that has nothing but the void that occupies it). More importantly, movement is possible only by virtue of there being the void. It is in this sense that “the void is a necessary condition for motion” (318).
The void thus performs two necessary functions for atoms, functions that are crucial not only to the distinction that the Atomists maintain against Parmenides but also to the very working of the ontology that they propose. Thus, while insufficient in itself (since empty), the void is necessary to the Atomist ontology. This is perhaps another motivation that the Atomists had for giving the void equal ontological status as what there is, since the atoms are able to do their work (the work assigned to them by Leucippus and Democritus) only by virtue of the presence of what is not, the void. It is in this way that the void is insufficient, but necessary—hence equal to the atoms ontologically.
Compounds: The Constituted Phenomenal World
Consistent to the temporal invariance inherent in the Atomist ontology (applicable to both of its elements, atoms and the void), atoms and the void are “eternally in motion,” lacking any initial state of rest or original lever for movement (318). As with all their other qualities, atoms and the void simply have always been and will always be in motion. The characteristic of the movement of a particular element at a particular moment in time, however, “is determined by [that element’s] immediately previous history” of contact with other atoms (318).
It can be deduced from this that “atoms move as the result of striking one another,” i.e. due to collisions, with the characteristics of their present movement determined by previous collisions (without any so-called first collision) (319). Aside from this “natural law,” as it were, “atoms do not have an inherent tendency either to be at rest or to move in any particular direction or towards any particular location” (319). In that sense, atoms “do not have any ‘natural’ motion” (319).
Products arise, however, out of certain collisions. As McKirahan explains, usually, when atoms collide, they rebound from each other, once again going off their separate ways (separated by, among other atoms, the void). There are instances, however, when colliding atoms “become entangled in virtue of the relation of their shapes, sizes, positions, and arrangements,” in which case these atoms “stay together,” forming compounds (323). In addition to size and shape, when composed into compounds, atoms may also differ in arrangement and position, i.e. their configuration in the compounds formed (322). Further differences thus become possible, which compound that fact that, as Barnes points out, no “single nature” characterizes compounds as naturally similar with each other in some way (except, that is, by their being composed of atoms and the void) (343).
These so-called compounds are then what “appear as water or fire or as a plant or a human,” i.e. virtually everything there is in the phenomenal world, i.e. the world as we experience it, the world that we know (McKirahan 323). Obviously, then, these compounds, unlike the atoms that compose them, have perceptible qualities, which are “due to the shape, size, arrangement, and position, and possibly the motions”—i.e. the structure rather than the inherent nature/quality—of the said atoms (323). It must be remembered that part of this structure is the void (as equal a part of compounds as atoms) that, as the other element, together with the atoms composes the compound. The void in this way also accounts for certain qualities of certain compounds (323).
Though composed by atoms (and the void) that are eternal, compounds are “not permanent,” not immutable (323). Compounds change due to “the spatial relations of atoms, [. . . being] generated and grow[ing] when atoms combine in appropriate ways; [. . .] decreas[ing] and [being] destroyed when the atoms separate; [. . .] alter[ing] (chang[ing] in quality) when the component atoms change their arrangements and relative positions” (324). Moreover, compounds “last until struck from outside in the right place by other atoms of sufficient size and appropriate shape, moving with appropriate speed” (323). By positing, then, the phenomenal world as a secondary world that is claimed to be constituted by fundamental elements (atoms and the void) that comply with the demands of the Parmenidean ontology, the Atomists are able to explain the change, difference, and impermanence characteristic of the phenomenal world while claiming to have resolved (or at least displaced) the Eleatic challenge.
Crucial to this move is the underlying assertion that “all things are atoms,” which claims that everything in the world are really but compounds of atoms (323). “There is nothing else,” as the Atomists say—except, that is, for the void, which is nothing and as such does not have to comply with the Parmenidean demands of being (323). Atoms and the void can thus be said as the “material cause” for what is experienced in the phenomenal world, for what is there and what comes to be (305, 315). It is in this sense that atoms (and the void) are the “building blocks” of the world (307). “All events are the necessary consequences of the interaction of atoms,” as McKirahan paraphrases (322). This is done, it must not be forgotten, through generation (by atoms and the void) “by means of their differences” (i.e. in shape, arrangement, position . . .), through which the diverse compounds of things we recognize in the world are formed (306).
Through the atomic theory, then, the Atomists are able to provide a possibility (foreclosed by Parmenides) as to how to “account for the macroscopic phenomenal world” characterized by plurality and difference (324). This, ironically enough, they do “in terms of the behavior of [. . .] microscopic atoms” that have many of the characteristics of Parmenides’ being (324). The atoms of Leucippus and Democritus are strikingly different from the “complex phenomenal world with its many different kinds of things, which behave in many ways,” yet these invariant and uniform entities—by being made infinite in number and coupled with another element, the void—are able to account for it (324). It is in this way that the Atomists present a substantive and interesting response to the Parmenidean ontology of their day.
Cosmogony, “Anthropology,” Epistemology
The Atomists developed a cosmogony explained by way of the ontology laid out above. Distinguishing the universe (“the whole,” i.e. everything there is) from the kosmos (a particular world system, a certain ordering of the whole), the Atomists explain that from all of the atoms and the void emerge an infinite number of worlds (kosmoi) that resemble one another (in form and in origin) (325). Each of these worlds, as McKirahan explains, emerges from a process (similar as the one at work with compounds) whereby due to atomic collisions and motions, a certain set of atoms is isolated, “creat[ing] a vortex in which similar atoms move toward one another” (325).
This vortex then forms a spherical membrane-like structure where smaller atoms are driven out and heavier atoms concentrate toward the center (326). From this process, an ordered system called a world or a kosmos may result. The use of the word may indicates that there is nothing inevitable about this process, which is simply a sequence of events that does not even guarantee the formation of a world (326). Similarly, no one kosmos is uniquely special (326). The worlds that result, however, once formed function according to the principles of atomism laid out above. Surprisingly, however, the laws of cosmology that the Atomists come up to explain heavenly phenomena have virtually nothing to do with the atomic theory (327).
Like the world itself (and unlike heavenly bodies), the human being, in the Atomist account, functions according to the principles of atomism (329). In fact, Democritus calls the human being a microcosm, “a small (mikros) kosmos” (329). The human being, however, like all other living things, differs from the world and the inanimate things in it “by the presence of the soul” (329) (my emphasis). The soul, like fire, consists of spherical atoms, signaling the changes it undergoes and its ability for motion (329). “The soul’s atoms are not destroyed at death, but disperse from the dead body” (329).
Human motion, as with motion in general, is explained by the Atomists as the “contact of the easily moving soul atoms with other atoms in the body” (330). Similarly, sensation “results from the contact of atoms,” the same as takes place with the sense of touch (330). Differences in the quality of sensations are accounted for by the differences in atomic shapes and arrangements (331). Distance between the atoms of the perceiving (i.e. the subject) and the perceived (i.e. the object) are overcome by the phenomenon whereby “physical objects give off [thin] films [of atoms] or effluences which enter our body through pores” (331). Thought itself—and human thinking in general—is accounted for by the same phenomenon—this time as “some of the films entering from outside affect the soul directly, not through the mediation of the senses,” leading to thoughts about things not present on immediate sensation, leading to thinking (332).
These operations of motion, sensation, and thought—i.e. the contact between atoms, near or far—is what, in the Atomist account, leads to knowledge, as films of atoms exuding from the objects being sensed meet films of atoms emanating from the subject perceiving. As McKirahan notes, there is both an objective and subjective component to this. On the one hand, sensations (the starting point of knowledge), as explained above, “do have an objective basis in reality (being caused by the atoms of the perceived object) and are not simply arbitrary fictions of our mind” (336). On the other hand, “the senses yield bastard judgment because they reveal perceptible qualities, which are properties not of atoms but of compounds, [. . . which, moreover] are not [. . .] objective properties that compounds have in their own right, but result from the interaction between the perceived object and the observer’s sense organs” (335). This compounds the earlier issue that sensations (on which, at least in the Atomist account, knowledge is based) are affected both by “the condition of the sensor” (i.e. the subject) and of “the sensed object” (331).
Thus the Atomists, unlike Parmenides, are able to provide some theoretical room for subjectivity and difference in perception (and hence in knowledge)—even while having an objective ground to that subjectivity. Things perceived are but compounds, which are but combinations of the elements that are really fundamental (atoms and the void) and are moreover merely presentations to the perceiver, which, as such, can appear different from individual to individual (based on individual’s own atomic structuration). The Atomists, yet again, are able to explain difference despite the sameness that grounds it, this time in the context of the same object being perceived differently by different observers.
Atomist epistemology, then, like cosmogony and the account of human beings in general, relies on the basic principles of the Atomist ontology. In other words, the structure and dynamic between atoms (and the void) are crucial for determining how motion, sensation, thought, and knowledge operate in the Atomist world. Thus the Atomists (like Parmenides) set up a truly thorough and comprehensive account (a cosmogony, “anthropology,” and epistemology) of the world—by virtue of an ontology that serves as its basis and defines its principles, as it were, from the center. Nonetheless, this ontology, by being posited at a primary level separated from the secondary world of phenomena, is able to take account of phenomena that themselves do not exist at the ontological level, phenomena such as change and difference. Yet another way in which the Atomist response to the Eleatic challenge is truly ingenious and notable.
Seeing as virtually everything in the Atomist world is defined by the interaction of atoms (and the void), it seems as though, ultimately, the account that the Atomists Leucippus and Democritus offer, even while taking account of difference and change, is mechanistically deterministic. As Taylor suggests,
The atomists’ universe is purposeless, mechanistic, and deterministic; every event has a cause, and causes necessitate their effects. Broadly speaking the process is mechanical; ultimately, everything in the world happens as a result of atomic interaction. The process of atomic interaction has neither beginning nor end, and any particular stage of that process is causally necessitated by a preceding stage. But exactly how the atomists saw the process as operating is obscure. (185)
Similarly, McKirahan reflects that “if all events are due to the mechanical motion and interaction of atoms in the void, atomism seems to entail a rigid determinism” (321). The necessity of the things that happen, however, as McKirahan continues, is but a “blind necessity” (321). That is to say, “as opposed to conscious or unconscious plan and purpose,” in the Atomist account things happen (phenomena take place, compounds emerge, atoms and the void interact in the way that they do) simply by virtue of “the nature of atoms and void” that the Atomists theoretically propose (321). Moreover, as the Atomist account has it, every phenomenon is accounted for merely by the immediately previous collision of atoms pertinent to it (and not by all movements in the world, which, moreover, are not even thought of by the Atomists as having been planned by some higher-order intelligent designer).
Thus the assertion that the Atomists are led to—the assertion that “there is a reason why everything takes place”—means not that “there is a governing mind, but [. . .] that every event has an explanation” (321). In other words, the Atomist account is deterministic only in a minimum way, at a basic level (the level of atoms and the void)—i.e. merely as a result of the nature of the ontology that the Atomists propose (which all ontologies are in one way or another necessarily going to entail)—an ontology that nonetheless provides room for all sorts of phenomena that evade mechanical determination—phenomena such as subjectivity, change, and difference—even while having a claim to validity in the way that it has measured up to Parmenides’ challenge. This is perhaps the reason why the Atomist account (or at least versions of it), including its individualistic implications, has manifested surprising longevity, its basic idea (of atoms and the void) appropriated for so long by mainstream science.
Barnes, Jonathan. The Presocratic Philosophers. New York: Routledge, 1982.
McKirahan, Richard D. Philosophy Before Socrates. Indianapolis: Hackett Publishing Company, 1994.
Taylor, C. C. W. “The Atomists.” The Cambridge Companion to Early Greek Philosophy. Ed. A. A. Long. Cambridge: Cambridge UP, 1999. 181-204.