> Because human behavior boils down to Plato vs Aristotle.

This is correct and the fundamental that distinguishes these two thinkers is the Primacy of Consciousness versus the Primacy of Existence, i.e., subjectivity versus objectivity. Kant's theories are a secularized, modernized version of Plato's ideas (i.e., removed the supernatural elements and replaced God with Society) whereas Rand's theories are a revised and more consistent version of Aristotle's ideas (i.e., consistently applied the law of identity to all branches of philosophy and especially to consciousness itself).

So the two poles of Western thought guiding human behavior are Plato/Kant versus Aristotle/Rand.