Descartes Meditations

Descartes opens with a reflection on the number of falsehoods he has believed during his life. He further reflects on the on the subsequent doubts of the basis of knowledge he has built up from these falsehoods. He has decided to remove all his knowledge and to start again from the beginning, building up his knowledge once more but this time on more certain grounds. He is alone, by the fire, free of all worries so that he can destroy his former opinions.

He concludes that he only needs to find some reason to doubt his present opinions in order to make him discard all his beliefs and start gaining a stronger foundation of knowledge. Instead of doubting his opinions individually, he feels it best to cast them all into doubt if he can doubt the foundations and basic principles upon which his opinions are founded.

Everything that he has accepted as most true he has come to learn from or through his senses. He acknowledges that sometimes the senses can be wrong and even deceive him but only when it regards objects that are very small or far away, and that our sensory knowledge on the whole is quite sturdy. Descartes acknowledges that insane people might be more deceived, but that he is clearly not one of them and needn't worry himself about that.

However, he realizes that he is often convinced when he is dreaming that he is sensing real objects. He is convinced that he is awake and sitting by the fire, but reflects that many times he has dreamed about this and subsequently convinced himself that it is real and true. Though his present sensations may be dream images, he suggests that images in our dreams are actually based on waking experiences for example paintings. When a painter creates an imaginary creature, like a mermaid, the composite parts are drawn from real things--women and fish, in the case of a mermaid. And even when a painter creates something entirely new, at least the colors in the painting are drawn from real experience. Thus, he concludes,...