What was Descartes' philosophical method?

Answer 1

Descartes' philosophy was deeply rooted in his desire to ascertain pure and certain knowledge. In order to accomplish this, he felt that he could not rely on what he had been taught, or what he thought he knew as he could not be absolutely assured that this was pure and uncorrupted information. Thus, he set out to formulate clear and rational principles that could be organized into a system of truths from which accurate information could be deduced. The principle that he came up with as a starting point for his philosophy was that of methodic doubt, that is, to doubt everything.

Descartes believed that we should not rely on our observations of the world around us, as these perceptions could be deceiving. To further this argument, he used the example of a dream. He stated that while we are dreaming, we believe that what is occurring in the dream to be true. Thus, there is no way of knowing whether or not what we perceive when we are awake is actually true, as, like when we are dreaming, it could simply be our senses deceiving us.

Consequently, Descartes believed that only those truths which he derived using reasoning, that is, reason and intuition alone, were reliable. Using his method of methodic doubt, Descartes came to his most famous realization, "I think, therefore I am." Of this, Descartes could be absolutely certain as regardless of whether his senses were deceiving him, he was still certain that he was having thoughts. From this premise, Descartes concluded that if there is something having thoughts, there must be a "thinker", and thus, he must exist.

Descartes continued to use methodic doubt as the premise for his philosophy, and from this starting point, came to many conclusions which he believed to be absolutely certain.