The roots of materialism: Parmenides

Whitehead looked at the history of philosophy and possible avenues for thought. He chose the process path starting with Heraclitus (who was alive in the same period as Parmenides) , a path that starts with the idea that Everything Flows.
The other main root of philosophy is the materialism of Parmenides, a Greek philosopher who lived around 5 B.C. He postulated that the world is made out of fixed objects. In The Way of Truth (a part of the poem), he explains how reality is one, change is impossible, and existence is timeless, uniform, and unchanging. In The Way of Opinion, he explains the world of appearances, which is false and deceitful. These thoughts strongly influenced Plato, and through him, the whole of Western philosophy.
As the phenomenal world appears to be made of objects and the practical difficulty posed by the process approach proved unpalatable for the majority, the materialism school became vastly more popular and stood largely unchallenged until the advent of scientific proof that the process path was the more accurate.