Does Descartes show we aren't dreaming?

Descartes' philosophy on reality actually shows that we cannot for sure know that we aren' dreaming. In fact, Descartes believed that we are not sure of anything, except for the fact that we exist because we use logic and reason.

Sorry that this doesn't answer your question, but the point of this ideology is for others to try to show Descartes how we know FOR CERTAIN that we are not dreaming right now....harder to do than one would think.