Daniel Miller- Part 4 of Descartes' Discourse- the mind/body distinction and God

After Descartes concludes with certainty that he must exist, he also concludes that he must be a thinking thing. For while the entire physical world could be doubted, the fact that he is thinking cannot. Because his physical body could be doubted but his mind could not, Descartes reasons that the mind must be separate from the body.
Descartes reasons that there are things more perfect than himself. He is doubting so many things, and it is better and more perfect to know than to doubt. Since his mind has ideas of things more perfect than he has (such as perfect knowledge), he must have gotten these ideas from a being more perfect than himself. In fact, this being must have all of the perfections which Descartes lacks yet can still conceive of. This perfect being is God. This argument was not novel, even in Descartes' time, for hundreds of years before him a philosopher/theologian named St. Anselm had already come up with a similar argument. This argument, reasoning from "that then of which no greater thing can be conceived" is called the ontological argument for the existence of God.

Sandy Rizzo-Part 4 of Discourse- Senses

In part 4 of Discourse, Descartes discusses how he feels that our senses are not reliable and that we can easily be deceived by them. He says that because of this, virtually everything that we've experienced or know through our senses can be doubted. If we doubt everything we know by our senses, we basically doubt everything in the world, which would mean there is no proof that anything exists. This is Descartes main point of this particular argument. He is saying that since our senses are unreliable, we can not trust that any type of knowledge we have received through them can possibly be true. I think a lot of people have a problem with this argument because we rely so heavily on our senses to tell us about the world, so when we can no longer trust them we are completely lost on how to gain knowledge about the world around us. I think that his argument has some good points and some bad ones. There are times when our senses deceive us, like when a rod is put in water and it appears to be bent, but that doesn't mean that all our senses can't be trusted. It is our senses that also tell us that the rod being bent under water is an optical illusion. I think we need to rely on our senses to an extent because we would go completely insane trying to figure out the world if we abandoned them.