As far as innate principles go, I always had assumed that everyone was born with them. But Locke brings up a rational argument in this aspect. He believes that people are not born with innate principles, because if we were, they would be immediately percieved at birth, and a human being must grow up, learn, and undergo experiences for any principle to become apparent to them; knowledge is learned in life, not innate. I like this argument very much because it is rational and makes sense unlike many of Descartes arguments. Descartes on the other hand believed that we have innated principles which are the basis for how we learn everything else. I believe Locke's rational is that when you are a baby, you can't talk, you don't know what anything is, and you don't have words or items to associate your thoughts with, therefore you have pretty much no memory of the time before you learned to speak and comprehend what is around you.