Long however before either Hobbes or Des Cartes the law of association had been defined, and its important functions set forth by Ludovicus Vives. Phantasia, it is to be noticed, is employed by Vives to express the mental power of comprehension, or the active function of the mind; and imaginatio for the receptivity (via receptiva) of impressions, or for the passive perception. The power of combination he appropriates to the former: “quae singula et simpliciter acceperat imaginatio, ea conjungit et disjungait phantasia.” And the law by which the thoughts are spontaneously presented follows thus: “quae simul sunt a phantasia comprehensa, si alterutrum occurrat, solet secum alterum representare.” To time therefore he subordinates all the other exciting causes of association. The soul proceeds “a causa ad effectum, ab hoc ad instrumentum, a parte ad totum;” thence to the place, from place to person, and from this to whatever preceded or followed, all as being parts of a total impression, each of which may recall the other. The apparent springs “saltus vel transitus etiam longissimos,” he explains by the same thought having been a component part of two or more total impressions. Thus “ex Scipione venio in cogitationem potentiae Turcicae, propter victorias ejus de Asia, in qua regnabat Antiochus.” But from Vives I pass at once to the source of his doctrines, and (as far as we can judge from the remains yet extant of Greek philosophy) as to the first, so to the fullest and most perfect enunciation of the associative principle, namely, to the writings of Aristotle; and of these in particular to the treatises De Anima, and “De Memoria,” which last belongs to the series of essays entitled in the old translations Parva Naturalia. In as much as later writers have either deviated from, or added to his doctrines, they appear to me to have introduced either error or groundless supposition.