In other words, yes he has found doubt in everything, but he now sees that his finding doubt in everything is something. Because he doubts, he must exist! He could doubt everything his senses told him. He could even doubt he had a body. But he could not doubt he had a mind because if he did not have a mind, how could he doubt? The steps Descartes takes to reach this conclusion also illustrate the underlying importance of ensuring he did not upset the Catholic Church. For example, Descartes makes sure to show there is a difference between the physical body and the mind. The mind or soul enables you to think, doubt, understand, etc.

People and animals have bodies, but only people have minds and souls and thus only people can think, doubt and go to heaven!

Although Descartes logic here calls into question a number of things, one of the most interesting objections to his argument and conclusion is the mind-body connection. Descartes unifies religion and science in his fundamental...

After all, cats and dogs have bodies but they do not doubt and thus do not have minds and souls. But what is it that keeps the mind and soul with the body; the body that relies on deceptive senses; the body that cats and dogs and pigs and horse all have? How is the soul connected to this deceptive body? What keeps it from floating around everywhere? Why doesn't it go hook up with an elephant? Descartes theory of dualism, the mind and body as two separate entities may have been reasonable for the Church to accept, but it was difficult for future thinkers to work with, especially because Descartes was eventually forced to name a physical part of the body as the actual location where the mind and body connected!
Bibliography

Palmer, Donald. Does the Center Hold? An Introduction to Western Philosophy. Boston: McGraw/Hill, 2002.