Meditations 1, Paragraph 8

In Descartes Meditations 1, paragraph 8, Descartes is saying how there are things that we can count on as being true, such as numbers and words. Yet, there are many other things that can be made to doubt. Things such as astronomy, medicine and physics. These theories in these topics have been disproven and changed to become "true" time and time again. We go by these theories everyday. Take medicine for example, we have all taken one form of medicine at one point in time or another. Medicine is a combination of materials to cure a symptom. Some very smart people trained in medicine took many hours to make the perfect formula to make this task successful. So, we take the pill. In a few days, we feel better. Was it the pill that did it or was it your body fixing itself. Your body is an extraodinary machine. If one has ever taken a biology course they know that statment is true. Your body could do wonderous things so why wouldn't it be able to heal it's own sicknesses? What i'm getting at is Descartes is right medicine is uncertain. Just because we go by it, does not mean it is true. It could be some other phenomenon such as our incredible body curing our pain. Who knows, in 10oo years maybe a chemist may find that advil does nothing to cure advil? It's far-fetched but how do you really know???