Epicurus 341 - 270 BCE (in the Hellenistic period) in Athens
Letter to Herodotus
Letter to Herodotus: Diogenes Laertius 10.34 - 83
Writing text as letters was a common genre in antiquity, and were meant to be read by the public.
Outlined in the beginning, the purpose of the letter were for those who could not work through the lengthy books, or for those who would benefit from a summary of the main doctrines.
According to Epicurus, the main goal for philosophical activity = a way to understand nature in order to bring calm to life (pursuing pleasure that is natural to obtain)
- his philosophy could be assumed as hedonism but he is not talking about excessive pleasures instead life without fear and with modest pleasure
“(37) Since this kind of method is useful to all those who are concerned with the study of nature, I recommend constant activity in the study of nature; and with this sort of activity more than any other I bring calm to my life. (p.6)
Epicurus’ Physical Doctrine
Epicurus was an empiricist saying that “it is also necessary to observe all things in accordance with one’s sense-perceptions” (p. 6)
First principle = something cannot come from nothing
The first point is that nothing comes into being from what is not; for (in that case] everything would be coming into being from everything, with no need of seeds. (pg. 6)
what exists =
“Moreover, the totality is [made up of] bodies and void; for in all cases sense-perception itself testifies that bodies exist, and it is by sense-perception that we must infer by reasoning what is non-evident, as I already said. 40. And if there did not exist that which we call void and space and intangible nature, bodies would not have any place to be in or move through, as they obviously do move. Beyond these two things [viz. bodies and void] nothing can be conceived, either by a comprehensive grasp or analogously to things so grasped … ” (pg. 6)
Epicurus provides his explanation that there exists bodies and voids based on the fact that sense-perception testifies the existence of bodies, and void must exist because otherwise, there would not be a place for the bodies to be in or move through.
“Further, among bodies, some are compounds, and some are those things from which compounds have been made. 41. And these are atomic and unchangeable, if indeed they are not all going to be destroyed into not being but will remain firmly during the dissolutions of com-pounds, being full by nature and not being subject to dissolution in any way or fashion. Consequently the principles of bodies must be atomic natures.” (pg. 7)
Here he outlines that bodies consist of atoms, and so are atomic in nature. He also outlines the principle of atoms, that they cannot be changed, destroyed or “subject to dissolution” in any way.
By Totality, Epicurus means the universe. For Epicurus, the totality is unlimited and it is unlimited “in respect of the number of bodies and the magnitude of the void”
For if the void were unlimited and bodies limited, bodies would not come to a standstill anywhere but would move in scattered fashion throughout the unlimited void, since they would lack anything to support them or check them by collision. But if the void were limited, the unlimited bodies would not have a place to be in. (pg. 7)
The number of atoms is infinite, but the number of shapes that atoms can have is finite (but ungraspable). This is because even if there was an infinite amount of shapes, then there would be an atom that would be large enough to see, which is not the case. And that a finite number of shape is sufficient for what is visible to us.
why are things not infinitely divisible?
- because if you divide something infinitely, you would get to something that would be too small that it is basically nothing or it would be too weak that it cannot do anything
- also Epicurus is supposing that if you divide something infinitely then you are also making it infinite in extent.
- so it makes sense to have a smallest thing that could make up bodies
“Consequently, not only must one eliminate unlimited division into smaller pieces (to avoid making everything weak and being forced in our comprehensive grasps of compound things to exhaust the things which exist by reducing them to non-existence) …” (pg. 11)
cosmoi = multiple of cosmos
- kind of similar idea that there would be multiple “solar systems” i.e. there would could be infinite number of (earth + sun + planets) systems
Moreover, there is an unlimited number of cosmoi, and some are similar to this one and some are dissimilar. For the atoms, which are unlimited (as was shown just now), are also carried away to very remote distances. For atoms of the sort from which a world might come to be or by which it might be made are not exhausted [in the production] of one world or any finite number of them, neither worlds like this one nor worlds unlike them. Consequently, there is no obstacle to the unlimited-ness of worlds.
The theory of Epicurus did not catch on because the argumentation for why atoms cannot be infinitely divisible was a weak argument and it was seem as absurd that there could be infinite cosmoi.
development of Epicureanism
Strato of Lampsacus (335 - 269 BCE)
- thought that Aristotle was wrong about the direction that air and fire moves. Aristotle believed that air and fire move upwards but Strato argued that they move downwards but are displaced by earth and water
- he also argued against Aristotle denying the existence of void
- For Strato, there were micro-voids
Strato devised an experiment as communicated by Hero of Alexandria
“Prepare a sphere, of the thickness of metal plate so as not to be easily crushed, containing about 8 cotylae (about 2 quarts). When this has been tightly sealed on every side, pierce a hole in it and let in a siphon, or thin tube of bronze, so that it does not touch the part diametrically opposite the hole but allows a passage for water, and so that the other end of the siphon projects about three fingers’ breadth above the sphere. The circumference of the hole through which the siphon is inserted must be sealed with tin applied both to the siphon and to the outer surface of the sphere, so that when we breath through the siphon, the air cannot possibly escape from the sphere. Let us observe what happens.” (trans. G.E.R. Lloyd)
If we can blow air or suck air into a sphere, then there must be micro-voids.
Mechanical philosophy developed as a continuation of Epicurus’ Atomism
Pierre Gasendi (1592 - 1655)
- he reworked Epicurus’ Atomism
- believed that atoms were created by God, and at creation, are endowed with a internal principle of motion (also called natural impulse, internal faculty or force)