Discourse On The Method Part III

Overview

With his method established, Descartes now faces a practical problem: how should he live while in the process of rebuilding his beliefs from the ground up? He can't simply suspend all action while he doubts everything, as life demands decisions. So he constructs a "provisional morality," a set of axioms to guide his conduct:

1. Obey the law and religion, maintaining the customs and traditions of his country
2. Be firm and resolute in action. Once a decision is made, follow through decisively, for "the actions of life often tolerate no delay"
3. Conquer yourself rather than fortune. Change your own desires rather than the order of the world. Descartes sees exercise and meditation as tools for this; when you push the limits of your physical nature, you realize that all you truly have is your thoughts
4. Find the best occupation of man, dedicating yourself to the most worthwhile pursuit

With these rules in place, Descartes sets out into the world as an observer. He extracts lessons from everything he encounters, even if the only takeaway is that a particular claim or experience holds nothing of value. Every observation yields something certain, if only by elimination.

Over time, he gains a reputation for having figured everything out. But Descartes himself realizes something different: he has learned all he can from the external world. The "book of the world" has been read. So he turns inward, isolating himself to dive deep into his own mind and psyche, setting the stage for the philosophical work to come.