III. Judgment as Related to Classification.
Judgment.—We have already spoken of that specific process by which, having formed a given conception, or a given rule, we bring the individual objects of perception and thought under that rule, or reject them from it, according as they agree or disagree with the conception we have formed. The process itself we have called classification. The mental activity thus employed is technically termed judgment—the power of subsuming, under a given notion or conception, the particular objects which properly belong there. Thus, the botanist, as he meets with new plants, and the ornithologist, as he discovers new varieties of birds, refers them at once to the family, the genus, the species to which they belong. His mind runs over the generic types of the several classes and orders into which all plants and birds are divided, he perceives that his new specimen answers to the characteristic features of one of these families, or classes, and not to those of the others, and he accordingly assigns it a place under one, and excludes it from the rest. So doing, he exercises judgment. All classification involves and depends upon this power; closely viewed, the action of the mind, in the exercise of this power, amounts simply to this, the perception of agreement or disagreement between two objects of thought. In the case supposed, the genus or species, as described by those who have treated of the particular science, is one of the objects contemplated; the next specimen of plant or bird, as carefully observed and studied, is the other. These two objects of thought are compared; the one is perceived to agree or not to agree with the other; and on the ground of this agreement or disagreement, the classification is made. This perception of agreement in such a case is an act of judgment, so called.
Not a distinct Faculty.—The form of mental activity now described, is hardly to be ranked as a distinct faculty of the mind, although it has been not unfrequently so treated by writers on mental science. It enters more or less fully into all mental operations; like consciousness and attention, it is, to some extent, involved in the exercise of all the faculties, and cannot, therefore, be ranked, with propriety, as coördinate with them. It is not confined to the investigations of science, but is an activity constantly exercised by all men. We have in our minds a multitude of general conceptions, the result of previous observation and thought. Every moment some new object presents itself. With the quickness of thought, we find its place among the conceptions already in the mind: it agrees with this, it is incompatible with that, it belongs with the one, it is excluded from the other. This is the form of most of our thinking; indeed, no small part of our mental activity consists in this perception of agreements and disagreements, and in the referring of some particular object of experience, some individual conception, to the class or general conception under which it properly belongs. The expression of such a judgment is a proposition. We think in propositions, which are only judgments mentally expressed. We discourse in propositions, which are judgments orally expressed. We cannot frame a proposition which does not affirm, or deny, or call in question, something of something.
Judgment in relation to Knowledge.—Are judgment and knowledge identical? Is all knowledge only some form of judgment? So Kant, Tissot, and other writers of that school, would affirm. "Judgment is the principal operation of the mind, since it is concerned in all knowledge properly so called." "All our knowledges are judgments. To know, is to distinguish, and to distinguish, is at once to affirm, and to deny." Such was also Dr. Reid's doctrine, in opposition to Locke, who distinguished between knowledge and judgment. Reid, on the contrary, regards knowledge as only one class of judgments, namely, those about which we are most positive and certain. According to this view, judgment seems to cover the whole field of mental activity. Sir William Hamilton thus regards it. We cannot even experience a sensation, he maintains, without the mental affirmation or judgment that we are thus and thus affected.
Common Speech distinguishes them.—It must be admitted, however, that in common use there is a distinction between knowing and judging, the one implying the comparative certainty of the thing known, the other implying some room and ground for doubt, the existence of opinion and belief, rather than of positive knowledge. The word itself, both in its primitive signification, and its derivation, indicating, as it does, the decision by legal tribunal of doubtful cases, favors this usage. That an exercise of judgment is, strictly speaking, involved in all knowledge, is, nevertheless true, since, to know that a thing is thus and thus, and not otherwise, is to distinguish it from other things, and that is to judge.
§ III.—Historical Sketch.
The Realist and Nominalist Controversy.
The Question at Issue.—No question has been more earnestly and even more bitterly discussed, in the whole history of philosophical inquiry, than the point at issue between the Realist and Nominalist, as to what is the precise object of thought when we form an abstract general conception. When I use the term man, for example, is it a mere name, and nothing more, or is there a real existence corresponding to that name, or is it neither a mere name on the one hand, nor, on the other, a real existence, but a conception of my own mind, which is the object of thought? These three answers can be made, these three doctrines held, and essentially only these three. Each has been actually maintained with great ability and acuteness. The names by which the three doctrines are respectively designated are, Realism, Nominalism, and Conceptualism.
Early History of Realism.—Of these doctrines, the former, Realism, was the first to develop itself. To say nothing of the ancients, we find traces of it in modern philosophy, as early as the ninth century. Indeed, it would seem to have been the prevalent doctrine, though not clearly and sharply defined; a belief, as Tissot has well expressed it, "spontaneous, blind, and without self-consciousness." John Scotus Erigena, and St. Anselm, Archbishop of Canterbury, both philosophers of note, together with many others of less distinction, in the ninth, tenth, and eleventh centuries, were prominent Realists. The Platonic view may, in fact, be said to have prevailed down to that period. The early fathers of the Christian Church were strongly tinged with Platonism, and the Realistic theory accordingly very naturally engrafted itself upon the philosophy of the middle ages. The logical and the ontological, existence as mere thought of the mind, and existence as reality, were not distinguished by the leading minds of those centuries. The reality of the thought as thought, and the reality of an actual existence, corresponding to that thought, were confounded the one with the other. As the rose of which I conceive has existence apart from my conception, so man, plant, tree, animal, are realities, and not mere conceptions of the mind.
Rise of Nominalism.—It was not till nearly the close of the eleventh century, that the announcement of the opposite doctrine was distinctly made, in opposition to the prevalent views. This was done by Roscelinus, who maintained that universal and general ideas have no objective reality; that the only reality is that of the individuals comprised under these genera; that there are no such existences as man, animal, beauty, virtue, etc.; that generality is only a pure form given by the mind to the matter of its ideas, a pure abstraction, a mere name.