 Aristotle
founded the Athenian school called the Lyceum. He
was the first philosopher to analyze the process
whereby certain propositions can be logically
inferred to be true from the fact that certain
other propositions are true -- all men are
mortal; Socrates is a man; therefore, Socrates is
mortal. |
 Democritus
suggested that all substance in the universe was
made up of particles so minute that nothing
smaller was possible. He regarded those particles
(atoms) as unchangeable and indestructible, and
as the only content of the universe besides the
very space in which they existed. |
 Empedocles
believed that all matter was composed of various
combinations and arrangements of four elements --
fire, air, water, and earth -- and that the
forces of Love and Strife acted on those elements
and caused them to mingle, separate, and
recombine. |
 Thales
of Miletus believed that all
substances come from water and will eventually
revert to water. He also made important advances
in the field of mathematics and was a careful
observer of the heavens. |
