Heraclitus and the Doctrine of Opposites and Universal Flux

Plato and Aristotle both attribute to Heraclitus the doctrines that
1) Everything is always changing
2) There is an identity of opposites, such as hot and cold.

Plato and Aristotle argue that these two doctrines are self contradictory because they entail that everything both is and is not at the same time.

Heraclitus, however, probably did not hold to a strong universal flux theory (textually evidenced), nor did he hold to a strict identity of opposites theory (also textually evidenced). Rather, it seems that Heraclitus held to a more moderate flux theory (while the water ever flows, the river itself stays the same and is in fact defined by the flowing water); and he held to a unity of opposites theory, as opposed to an identity of opposites theory. In other words, it is not the case that hot is equal to cold, but that hot and cold are united in their exchange. X can go from hot to cold and back again. It does not go from hot to apricot and back again. Hot and cold are in fact a unity.

What Heraclitus gives us then is not a contradiction, but, rather, a more interesting question regarding persistence through change, i.e., identity. What are the conditions for x to persist through change.

The Sophists, Socrates, and Heraclitus

The Sophists leaned heavily on a skepticism of the intellect, and thus they trained their students in the art of persuasion, rather than the art of discovery. The Sophists were also skeptical about morality. Socrates is most famous for challenging the Sophists about their skepticism. Socrates transformed our understanding of the oracle's decree "know thyself". For him, the decree meant the art of self discovery in relation to the truth, as opposed to the traditional meaning, that everyone should know who they are in relation to society.

Heraclitus: "Nature loves to hide herself". He taught that all things are made of strife, but that very few are interested in discovering the truth about reality. Heraclitus has three main doctrines, of which we covered part of the first: the doctrine of opposites, which states that nothing can be known or can exist independently of its relation to its opposite. Nature is like a bow, it functions according to the tension of its parts, just as a bow gets its strength when pulled back. And just as a bow cannot be understood with understanding the tension it produces, so too nature cannot be understood with understanding that reality is a conjunction of its opposites. Hot requires cold, love requires hate. "The way up and the way down are the same."

Pre Socratic Philosophy Before Heraclitus and Parmenides

Thales wasn't the first philosopher. The first person to wonder was. Thales, however, was the first we have recorded of asking the question of origins without recourse to religion. His questions were essentially, what is the source of all things, and is the source one or many. Anaximander followed closely behind Thales with the first recorded philosophical debate. He argued that water, which Thales thought was, could not be the source of all things, because water is by nature differentiated. You can't get something from what is not there, and it doesn't appear that water can produce all things. Rather, Anaximander argued that "the unbounded" or "apeiron" was the source of all things, because only the unbounded could be undifferentiated enough to produce all things. What is interesting is that Anaximander resorted to arguing for something essentially unobservable. So we have our first real debate: can there exists non-observable entities? Can such an entity be the source of all things?