ATOMISM

philosopher Lucretius (c. 99 - 55 B.C.) whose "On the Nature of Things" was one of the definitive works of Epicureanism, but also of Atomism. It argues that the universe and all substance is eternal, composed of atoms moving in an infinite void and nothing else, and that the human soul also consists of minute atoms that dissipate into smoke when a person dies. 

Nicolaus Copernicus (1473 - 1543) and Galileo Galilei (1564 - 1642), who himself converted to Atomism when he found that his corpuscular theory of matter and his experiments with falling bodies and inclined planes contradicted the mainstream Aristotelian theories.

The English philosophers Sir Francis Bacon and Thomas Hobbes were both confirmed Atomists for a time, as was Giordano Bruno in Italy.

The main figures in the rebirth of Atomism were the French philosophers René Descartes, Pierre Gassendi, and the Irish philosopher and scientist Robert Boyle.

Descartes’ mechanical philosophy of corpuscularism (that everything physical in the universe is made of tiny “corpuscles” of matter, and that sensations, such as taste or temperature, are caused by the shape and size of tiny pieces of matter) had much in common with Atomism, and may be considered in some sense another version of it, although for Descartes there could be no void, and all matter was constantly swirling to prevent a void as corpuscles moved through other matter. 

He formulated his atomistic conception of mechanical philosophy partly in response to Descartes, particularly opposing Descartes’ reductionist view that only purely mechanical explanations of physics are valid.

Robert Boyle's form of Atomism, which came to be accepted by most English scientists, was essentially an amalgamation of the two French systems. He arrived at it after encountering problems reconciling Aristotelian physics with his chemistry experimentation.

Philosophical Atomism led to the development of early scientific atomic theory, modern science has shown that atoms in the chemical sense are actually composed of smaller particles (electrons, neutrons and protons), and that these in turn are composed of even more fundamental particles called quarks. Although the principle can still theoretically apply, there are few, if any, modern-day atomists.