Are these homework questions?

Hume is famously an empiricist while Descartes is a rationalist. I'd recommend the Stanford Encyclopedia of Philosophy for further explanation - it's free online. Read their respective articles on that site and you'll find the answers to these questions.

Never mind. Yesterday I found out that I was pretty successful in answering those questions myself without the Stanford encyclopaedia. Though it gave me the reassurance, which I needed.

Descartes held we can only have certain knowledge of our own thinking processes. His reasoning was predicated on his own doubt. He , split the human person into the material substance of the body and the spiritual substance of the mind. His uncertainty of matter and certainty of thought was separated into the mechanical body and the animation of thought. He conceived a philosophy that views certain knowledge from within the human mind alone. This distinction influenced Hume to deny certainty of the spiritual or material world, nurturing a skepticism remaining with us to this day. For Hume, 'There is no foundation for any conclusion a priori, which 'tis possible for the human mind to form a conception.'[1] That is to say beyond our sensory experience knowledge is dubious, thus we cannot make a move, or even a leap, toward questions of ultimate reality.

[1][2] Hume, David, L. A. Selby-Bigge, and P. H. Nidditch. A Treatise of Human Nature. Oxford: Clarendon Press, 1978.