What the ultimate Natural Units of material are?

Plato's Primal Substances

In his Timaeus, Plato (427-347 BC) postulated that combinations of four primal substances: air
water
fire
earth
made up all materials. He associated the regular (platonic) solids with his primal substances: cube with earth, tetrahedron with fire, octahedron with air, icosahedron with water, and dodecahedron with ether.

Plato's student Aristotle (384-322 BC) examined the ideas of primal substances from the viewpoint of causes and effects. He believed in having a limited number of primal materia, but added four qualities:

hot
cold
wet
dry
.
In his mind, a combination of these qualities and primal substances caused all the phenomena of the world.

EARTH wet WATER
hot cole
FIRE dry AIR

Plato's primal substance concept dominated scholarly thought for almost 2000 years.

E-mail: cchieh@uwaterloo.ca