 Each of the several substantive first principles of practical reason picks out and directs one towards a distinct intelligible good which, in line with the primariness of the principle identifying it, can be called “basic” (not a term used by Aquinas). Aquinas regards each of the first practical principles as self-evident (per se notum: known through itself) and undeduced (primum and indemonstrabile). He does not, however, mean that they are data-less “intuitions”; even the indemonstrable first principles in any field of human knowledge are knowable only by insight (intellectus) into data of experience (here, of causality and inclination).