In old Athens, they were giving Aristotle, the founder of Classical Logic, a hard time.
The philosophers in the generation before Aristotle, more alert to the Self-Loop, were bickering about the Principle of Contradiction. And this, Aristotle thought was just not fair.
[Modern Scientists and Philosophers are made of tougher stuff. They don’t wait for approval from any Village-Elder.]
In Metaphysics, Aristotle complains:
‘Those who are genuinely perplexed believe…[the] co-presence of contraries is an elementary fact..
So Anaxagoras declares everything to be mingled in everything else.. Democritus too says that the Void and the Plenum are alike present in any part..
Empedocles say’s: ‘As men themselves changed, so came a corresponding change of mind.’ Homer too is said apparently to have held the same opinion.
Parmenides declares himself..in the same way: ‘What fills [Man’s] body fills his thought.’
Xenophanes [who was the teacher of Parmenides] seems not to have understood..material or formal explanation, but gazing at the whole sky says: ‘Unity is God!’.
And from this conviction there blossomed the most extreme of their doctrines, the philosophy of Heraclitus as held by Cratylus, who finally thought one ought not to speak at all, but simply pointed his finger and censured Heraclitus for saying that it is impossible to step into the same river twice–for he himself believed that one could not do so even once.’