Descartes vs Hume

Cakesistence
    I am hosting a dinner party at my house.   I have invited 2 friends over to join me.   One is a Humean empiricist and the other a Cartesian rationalist.   We have all eaten and I walk into the room with a few slices of chocolate cake.   I put them down on the table and pause, I turn to my friends and say, “We can never really know anything about the world around us, or even much about ourselves.”   To prove my point, I draw everyone’s attention to the chocolate cake on the table. “How can we really know,” I ask, “whether there really is chocolate cake on the table, what chocolate cake really is, and whether chocolate cake is good for us or not? Descartes, why don’t you go first?”
    Descartes would explain that in order to determine if there is a piece of chocolate cake on the table, he would need to determine if he, himself, exists.   After all, if Descartes does not exist, how can he make a determination if the cake exists?   As Descartes has written in “Meditations on First Philosophy” he explains that he must exist as a result of having a mind that thinks.
Next, Descartes would analyze his senses.   He would explain, “The slice of cake tastes sweet, feels fluffy and warm, looks brownish in color and triangular in shape, and has a cocoa scent, but why does the cake taste, feel, look, and smell this way?”   Descartes would explain what his senses observed did not make the slice of cake, cake.   The taste, feel, color, shape, and scent, can all be taken away and it would still be a slice of cake.   But is there really chocolate cake on the table, or is it all just a dream?
Descartes wrote about his search of the existence of God, and if God is infinitely perfect, or a deceiver.   He concluded that an infinitely perfect God does exist, who is not a deceiver.   Descartes cannot be dreaming that he is observing this piece of cake on the table as a result of God’s will to deceive him.   Also, Descartes would know that he is not dreaming because his perception...