Regulae

In 1628, or perhaps a few years earlier, the rationalist René Descartes (1596 – 1650) began work on a treatise, left unfinished, on the correct method for scientific and philosophical thinking, entitled "Regulae ad directionem ingenii," or "Rules for the Direction of the Mind." To honor his effort, the first volume of "Regulae" gathers a hundred rules covering the game of truth. This sport, played by scientists and philosophers alike, aims to enlarge conceptual knowledge (synthetic propositions a posteriori valid pro tem). In a second volume, beauty (aesthetics) is dealt with, and in a third, action (ethics).