_Mental Reproduction, and mental Recognition as distinguished._--This power operates in various forms. There may be the simple representation of the absent object, without reference to the act of former perception, as when I think of the Strasburg tower, without recalling any particular instance of its perception. Or there may be such recalling of the former act and instance of perception. The thought of the tower, as it presents itself to my mind, may stand connected definitely with the idea of the time, and place, and attending circumstances in which, on some occasion, I saw that object. It is then _recognized_ as the object which was seen at such or such a time. The former is an instance of _mental reproduction_ simply--the latter, of _mental recognition_. We have in common language but one name for the two--although the term mare strictly belongs only to the latter--and that is, _Memory_. _Representation of the Ideal in distinction from the Actual._--Again, unlike either of these, there may be a conception and representation of the object, not at all as it is in reality, and as it was perceived, but varied in essential particulars, to suit our own taste and fancy--a tower not of ordinary stone, but of some rare and costly marble--not of ordinary height, but reaching to the skies, etc., etc. In the former cases we conceived only of the _actual_, now of the _ideal_. This faculty is called _Imagination_. Both are forms of the representative power, not _presenting_, but only _representing_ objects. _Conception of the Abstract._--_The Discursive or Reflective Power._--In the cases thus far described we have conceived of some sensible object, considered in and by itself, capable of being represented to thought. We may, however, conceive not of an object in itself considered, but of the properties and relations of objects in the abstract. Thus we compare and class together those objects which we perceive to possess certain properties in common; as books bound in cloth, or in leather, octavos, or duodecimos. In so doing we exercise the faculty of _generalization_, which involves comparison, and also what is usually termed abstraction. Or we may reverse the process, and instead of classing together objects possessing certain elements in common, we may analyze a complex idea, or a comprehensive term, in order to derive from it whatever is specifically included in it. Thus from the general proposition, "All men are mortal," inasmuch as the term "all men" includes Socrates, I infer that Socrates is mortal. The process last named is called _reasoning_.