Posthumous tracts

SEVERAL years have now elapsed since I first conceived the design of working out the problems of rational psychology, or what amounts to the same thing, of investigating the essence and faculties of the human soul and internal senses; but hitherto the extreme difficulty of the subject, coupled with the vast amount of preliminary knowledge which is requisite, have warned me against treading prematurely in this direction; for much must previously be reduced to a clear statement and a distinct order.