  Leibniz is often put in the camp of rationalists and opposed to the empiricists (for example, Locke, Berkeley, and Hume). While there are good grounds to be unhappy with this standard textbook distinction, Leibniz does fit the bill in two important respects: he is a rationalist insofar as he holds to the Principle of Sufficient Reason, and he is a rationalist insofar as he accepts innate ideas and denies that the mind is at birth a tabula rasa or blank slate. In terms of Leibniz's classical allegiances, it is interesting to see that in the realm of metaphysics, he often couched his philosophy in Aristotelian (and Scholastic) terms but that in the realm of epistemology, he was a fairly open Platonist – at least in terms of the existence of innate ideas. Indeed, in the opening passages of his New Essays on Human Understanding, his book-length commentary on Locke's Essay Concerning Human Understanding, Leibniz explicitly aligns himself with Plato on the fundamental question of the origin of ideas. (A VI vi 48/RB 48)