"A Discourse of a Method for the Well Guiding of Reason" by René Descartes is a philosophical and autobiographical treatise published in 1637. Descartes confronts the problem of skepticism by doubting everything to achieve a fresh perspective. Through this radical method, he arrives at an incontrovertible truth that becomes philosophy's most famous statement. The work presents four precepts for guiding reason and seeking truth in the sciences, establishing foundations for modern philosophy and natural sciences while introducing concepts that would revolutionize mathematics and human thought.
Wikipedia page about this book: en.wikipedia.org/wiki/Discourse_on_the_Method