Philosophy of matter

Philosophy of matter is the branch of philosophy concerned with issues surrounding the ontology, epistemology and character of matter and the material world. The word matter is derived from the Latin word materia, meaning "wood", or “timber”, in the sense "material", as distinct from "mind" or "form". The image of wood came to Latin as a calque from the ancient Greek philosophical usage of hyle (ὕλη). In ancient Greek philosophy, arche (ἀρχή) is the beginning or the first principle of the world. Thales of Miletus claimed that the first principle of all things is water. His theory was supported by the observation of moisture throughout the world and coincided with his theory that the earth floated on water. Thales's theory was refuted by his pupil and successor, Anaximander. Anaximander noted that water could not be the arche because it could not give rise to its opposite, fire. Anaximander claimed that none of the elements (earth, fire, air, water) could be arche for the same reason. Instead, he proposed the existence of the apeiron, an indefinite substance from which all things are born and to which all things will return. Anaximenes, Anaximander's pupil, advanced yet another theory. He returns to the elemental theory, but this time posits air, rather than water, as the arche. Anaximenes suggests that all is made from air through either rarefication or condensation (thinning or thickening). Rarefied, air becomes fire; condensed, it becomes first wind, then cloud, water, earth, and stone in order. Pythagoras of Samos, a mathematician, mystic, and scientist, taught that number, rather than matter, constitutes the true nature of things. He seems to have influenced Socrates' ideal form. Heraclitus held that all is flux. In such a system there is no need for or possibility of matter. Leucippus held that there exist indivisible particles, atoms, underlying existence. Empedocles held that there are four elements, from which things are derived, Earth, Water, Fire and Air. Some added a fifth element, the Aether, from which the heavens were derived.