Thales gave rise to philosophy by relying on sensory experience and reason. The next philosopher in line — Heraclitus — not only trailed a different path, but ignited a chain-reaction that ran through history toppling like dominos all that man tried to erect with his reason. It all began with the problem of change and multiplicity; it all ended with my thirteen-year-old niece asking petulantly: “Why can’t I simply decide I am a boy?”
Thales was happy to explain change by finding in water a common denominator of all things. That meant water was everywhere, but appearing in different forms. Everything was water (change didn’t imply an all-out substitution), yet it wasn’t (it could change somewhat, after all). Therefore, Heraclitus concluded, everything is and isn’t at the same time: the world is full of contradictions. The Law of Identity — A is A — does not apply. The Law of Non-Contradiction — A can’t be A and non-A at the same time in the same respect— is a falsehood. My niece is right.
Like all philosophers at that time, Heraclitus wanted to find the “one in the many”, the “unity in multiplicity”, that primeval substance that underlies it all. But all he saw pervading the world was change itself, not any kind of permanent substance (he eventually picked “fire” more as a metaphor for pure motion than as a metaphysical “stuff”). The metaphysical essence of reality is change. “You can’t step in the same river twice”, he supposedly said. Everything is in flux; nothing stands still.
So, he can be considered the idol of those evaders that, unhappy with their very existence, find solace in the fact that everything changes. They confound the metaphysically given with the man-made and just await for better times, wishing they were different. But Heraclitus really meant it: you cannot step into the same river twice not only because the river has changed, but because you too have changed. Whoever stepped the first time no longer exists to step the second time — persons do not exist. Sorry.
Heraclitus’ real legacy, though, was his conclusion from the premisse that all is changing all the time: that the senses are invalid. We see a lot that is motionless, unchanging. That is undeniable. But, at the same time, that cannot be; we must be deceived. We can only know reality through reason, he tacitly said. Heraclitus, therefore, is the father of Rationalism. But even more important, he is the father of Dualism, because now two different realms coexist: reality and appearance.
The end-result of Heraclitean influence across the millennia is the blatant relativism so prevalent today, the idea that there are no absolutes, that everything is relative. What I want most from my philosophical escapades is to show how wrong that is. I see absolute truths all around me in combat, in death, in life — what happens after I press the trigger is always an absolute.
However, I can’t wish that my niece go into combat. And I still need to answer her.
1. Soon after Thales, Anaximander and Anaximenes (the other two philosophers of the Milesian school) basically proposed a rehash of his monistic metaphysics where only the primordial substance would be different, without great innovations or lasting influences. I think that is the reason why Leonard Peikoff simply ignored them in his course.