Descartes method of doubt

Essentially, Descartes' philosophy was based on the notion of methodical doubt, that is, to doubt absolutely everything that one could not be absolutely certain of. Descartes considered the principal weakness of his predecessor's philosophy to be its subjectivity. He felt that the premises from which previous philosophers deduced truths were not necessarily accurate, and thus did not provide any intellectual certainty. Consequently, Descartes used methodical doubt as the starting point for his philosophy.