But although we have recorded as examples these general treatises on the passions, it would be impossible to continue the enumeration, because descriptive psychology is carried out, so to speak, with the widest divergences and is infinitely subdivided. An ample bibliography would not suffice to catalogue all the books dealing with this discipline. These are sometimes arranged in chronological divisions (Psychology of the Renaissance, of the eighteenth century, of the Middle Ages, even including prehistoric man!). Sometimes they contain geographical divisions (Psychology of the Englishman, of the Frenchman, of the Russian, of the Japanese, and so on), with subdivisions according to regions. Sometimes they combine the two methods (Psychology of the ancient Greek, of the Roman of the Decadence), and sometimes according to their psychical content (Psychology of the priest, of the soldier, of the politician, of the poet, of the man of science), and so on. And when the treatises that bear a title of the kind above mentioned had been catalogued, it would be also necessary to trace a great mass of descriptive psychology (and of the best sort) in the books of historians, novelists, dramatists, in memoirs and confessions, in maxims and advice for the conduct of life in the sketches of satirists and caricaturists. And when all these had been catalogued (a very difficult task), it would be necessary to take account of all the other psychology, which, formed in the spirit of individuals who are not writers, is poured forth in speech. This is found, but in small part, in collections of proverbs. It would also be necessary not to neglect (an altogether desperate enterprize) everything that each one of us does and forgets and substitutes continually in life, according to his own needs and experiences. _Tantae molis_ would be a complete account, precisely because psychological construction, having for its object actions and individuals in action, is of such common use. [Sidenote: _Normative knowledge or rules: their nature._]