It does not belong to our purpose to consider either the theological or the metaphysical doctrines which form so large a portion of the treatises of the schoolmen. Perhaps it may hereafter appear, that some light is thrown on some of the questions which have occupied metaphysicians in all ages, by that examination of the history of the Progressive Sciences in which we are now engaged; but till we are able to analyze the leading controversies of this kind, it would be of little service to speak of them in detail. It may be noticed, however, that many of the most prominent of them refer to the great question, "What is the relation between actual things and general terms?" Perhaps in modern times, the actual things would be more commonly taken as the point to start from; and men would begin by considering how classes and universals are obtained from individuals. But the schoolmen, founding their speculations on the received modes of considering such subjects, to which both Aristotle and Plato had contributed, travelled in the opposite direction, and endeavored to discover how individuals were deduced from genera and species;--what was "the Principle of Individuation." This was variously stated by different reasoners. Thus Bonaventura[76\4] solves the difficulty by the aid of the Aristotelian distinction of Matter and Form. The individual derives from the Form the property of _being something_, and from the Matter the property of being that _particular thing_. Duns Scotus,[77\4] the great adversary of Thomas Aquinas in theology, placed the principle of Individuation in "a certain determining positive entity," which his school called _Hæcceity_ or _thisness_. "Thus an individual man is Peter, because his _humanity_ is combined with_ Petreity_." The force {234} of abstract terms is a curious question, and some remarkable experiments in their use had been made by the Latin Aristotelians before this time. In the same way in which we talk of the _quantity_ and _quality_ of a thing, they spoke of its _quiddity_.[78\4] [Note 76\4: Deg. iv. 573.] [Note 77\4: Ib. iv. 523.] [Note 78\4: Deg. iv. 494.]