Of Apollonia (on the Black or Euxine Sea), is generally reckoned the last of the Presocratic philosophers. The best evidence of his date is Aristophanes' Clouds (423 bc), where his views are parodied.
Diogenes' central argument defended an Anaximenean form of material monism (see anaximenes ). The first move established the truth of monism as such: interaction between bodies would be impossible if they were essentially different. Next came proofs reminiscent of Anaxagoras that there is much intelligence in the world, as witness its orderly structure and the life of men and other animals. From this Diogenes inferred his principal thesis: the basic body must be air, since air is what pervades and disposes all things and supports life and intelligence. Differentiation in air explains differences between species. The causal connection between air and life and intelligence was substantiated in a detailed account of the blood channels. Diogenes evidently applied his causal scheme systematically. Theophrastus has a long passage on the senses, and many physical phenomena were explained on the analogy of sweating and absorption of moisture (e.g. magnetism, the flooding of the Nile).
Subjects: Classical Studies.