Rules for the Direction of the Mind

Regulae ad directionem ingenii ( German: Rules to align the power of knowledge or Rules for the Direction of the Spirit ) is an unfinished work of René Descartes, which he began in 1619 and was originally intended to include 35 rules, but ultimately it was limited to 21. The fragment formed the basis for his later work on complex problems of mathematics, science and philosophy, and in particular the 1637 anonymously published Discours de la méthode pour bien conduire sa Raison.

The first 12 rules treat his proposed scientific method in general; its content has been elaborated in more detail in later works.