Rules for the Direction of the Mind

36 rules were planned in total. Rules 1-12 deal with the definition of science, the principal operations of the scientific method (intuition, deduction, and enumeration), and what Descartes terms "simple propositions", which "occur to us spontaneously" and which are objects of certain and evident cognition or intuition. Rules 13–24 deal with what Descartes terms "perfectly understood problems", or problems in which all of the conditions relevant to the solution of the problem are known, and which arise principally in arithmetic and geometry. Rules 25–36 deal with "imperfectly understood problems", or problems in which one or more conditions relevant to the solution of the problem are not known, but must be found. These problems arise for the most part in natural philosophy and metaphysics. However, the work ends prematurely at rule 21.

Rules