LEUCIPPUS AND DEMOCRITUS. Leucippus and Democritus were the earliest Greek atomists. The originator of the atomic theory, Leucippus (fifth century BCE), must be considered a speculative thinker of the first order, but to Democritus (c. 370 BCE) must go the credit for working out the detailed application of the theory and supporting it with a subtle epistemology. Democritus of Abdera lived from about 460 to 370 B.C. Along with Leucippus, an older philosopher whose dates are uncertain, he is the founder of the atomic philosophy of nature. Atomism is the most influential of the philosophies of nature to be developed prior to the time of Socrates (d. Contribution to atomic theory 'By convention bitter, by convention sweet, but in reality atoms and void'. Democritus said that everything is made up into tiny bits, which are called. The atomists of the time (Democritus being one of the leading atomists) believed there were two realities that made up the physical world: atoms and void. There were an infinite number of atoms, but different types of atoms had different sizes and shapes. The void was the empty space in which the atoms moved and collided with one another. Democritus is one of the most influential people in the chemistry. He was the first person who discovered the theory of atom. We know his discovery as Democritus theory of atoms. This theory is one of the most important theory in the atomic theory and organic chemistry in general.
Ancient vs. Modern Atomism This very compelling world-view has given rise to a mechanistic, deterministic, point of view that has been even more popular in modern times than it was in ancient times. (Contemporary problems about deterministic physics arising from quantum mechanics have considerably weakened the support for this point of view. The classical Newtonian view that quantum theory has replaced is basically Democritean.)
The ancient atomists may appear to have provided a brilliant anticipation of a much later scientific theory. But is this picture accurate? Our enthusiasm for the achievements of the ancient atomists must be tempered by a closer look at the basis of their view.
Their impetus did not come from physical inquiries, but from the logical and metaphysical positions of Parmenides and Zeno. As Barnes says (Presocratics, p. 346: “the first atoms came from Elea.” Atoms were postulated in response to the Eleatic view that a truly real entity must be one and indivisible. So we must ask: In what sense were Democritus’s atoms indivisible? Democritus might have meant either of the following:
- It is physically impossible to divide an atom.
- It is logically or conceptually impossible to divide an atom. If (a) is the Democritean position, then it would make sense to talk about the parts of an atom - there might even be such parts - although it would not be physically possible to separate the parts.If (b) is what Democritus maintained, then this sort of talk makes no sense. The very idea of “splitting an atom” would represent not just a technological difficulty (or even a technological impossibility) but a conceptual absurdity.
Democritus Year Of Discovery
Opinion is divided on this issue.- In favor of (a) are
- Burnet (EGP, p. 336):
We must observe that the atom is not mathematically indivisible, for it has magnitude; it is however physically indivisible, because, like the One of Parmenides, it contains no empty space.
- KRS, p. 415:
[An atom] is presumably only physically, not notionally, indivisible, since for example atoms differ in size.
- Burnet (EGP, p. 336):
- In favor of (b) are
- Guthrie (vol. 2, p. 396):
Democritus held that his atoms, being not only very small but the smallest possible particles of matter, were not only too small to be divided physically but also logically indivisible.
- Furley: I will give a quick sketch of the case he makes for (b).
- Guthrie (vol. 2, p. 396):
Democritus Atomic Model Name
- Aristotle says that atoms were postulated to meet (what he called) Zeno’s “Dichotomy Argument.” This would be either the paradox of the race course, or the paradox of plurality.
- But, as we have seen, both of these arguments of Zeno’s are meant to show that infinite divisibility (whether physical or theoretical) leads to absurd results. Hence,
- The atomists would not be meeting Zeno’s argument unless they conceived of atoms as both physically and theoretically indivisible. Furley (p. 510):
A theoretically divisible atom would not answer either of Zeno’s arguments. [The plurality paradox] would show that an atom theoretically divisible to infinity must be infinite in magnitude; and [the race course] would show that such an atom could never be traversed - that is, if one starts imagining it, one can never imagine the whole of it.
Furley’s conclusion is supported by further evidence from Aristotle, who claims that atomism conflicts with mathematics (De Caelo Add spotify to mac dock. 303a20): Windows updates to support Microsoft Edge.
They must be in conflict with mathematics when they say there are indivisible bodies.
But an atom that is (merely) physically unsplittable would not conflict with mathematics.
Democritus Atom
If this interpretation is correct, and atoms are theoretically indivisible, then the differences between the Democritean view and modern scientific atomism are greater than the similarities.
Objections to theoretically indivisible Democritean atoms.
Democritus Atom Experiment
- According to Simplicius, Democritus thought that atoms had size and shape:
5=A37: For some of them are rough, some are hooked, others concave and others convex, while yet others have innumerable other differences.
27=A14: These atoms, which are separate from one another in the infinite void and differ in shape and size and position and arrangement, move in the void . . . . - But it is hard to see how someone could conceive of atoms as having size and shape, and still being theoretically indivisible. For it would seem that, for any size x, we can always think of something that is only half that size: we can always divide x by 2.