A Discourse of a Method for the Well Guiding of Reason / and the Discovery of Truth in the Sciences

The author sets out a compact program for using reason to discover scientific truth. He begins with reflections on the state of the sciences and his own intellectual practice, then formulates a method consisting of clear and distinct principles: accept only evident beliefs, divide difficulties, proceed from simple to complex, and enumerate thoroughly. He derives moral maxims from this method, offers arguments for God's existence and the distinction of the human soul, and reports physical inquiries including an account of cardiac motion and differences between human and animal souls. He concludes with proposals for continuing natural investigations and an appeal to combine rigorous thought with experiment.