ART. I. -- NATURE OF UNIVERSALS.
34. A universal is that which is found in many or may be affirmed of many; it is the essence of a being or the intelligible object perceived by the intellect.
35. The question of the nature of universals is closely connected with that of the origin and nature of ideas. -- Ideas are universal; by them we apprehend the universal. The solution of the problem of ideas is, therefore closely connected with that of the problem of universals, nor is the latter problem less important than the former. As universals are the proper object of our intellectual knowledge, we can easily understand the lively controversy to which the question of universals has given rise in the history of philosophy.
36. To account for the true nature of universals, we must distinguish 1. the direct universal, which is the essence considered merely in itself, by a direct act of the intellect; 2. the reflex universal, which is the essence considered by a reflex act of the intellect, as common to many individuals. -- The essence of a material being abstracted from its individuating conditions is the proper object of the intellect. But the intellect may perceive the essence by a direct act, or it may return to consider the idea of this essence by a reflex act. In the first case, the intellect merely perceives the essence with its intrinsic characteristics, without considering whether it is single or multiple, real or ideal. Thus the intellect, by a direct act, represents to itself the essence of man, conceives him as a rational animal, but does not consider whether this essence is found in a single individual or in many individuals, whether it exists really or ideally.
Evidently the direct universal is not, strictly speaking, a universal; it is said to be so as opposed to individuals, and also as being the basis of the reflex universal, which is the universal, strictly speaking. In order to form this universal, the intellect reflects upon the essence which it has apprehended directly; it views the idea as representing an essence common to many individuals. Thus, after the perception of the essence of man as a rational animal, the intellect reflects upon the idea of this essence, and recognizes that it expresses the human nature in which all men are alike. This distinction arms us with a ready answer to the objection that the universal cannot be drawn from the particular, since the greater cannot proceed from the less. If the reflex universal is meant, evidently it is not found in the particular; but if it be the direct universal, the answer is that this universal is actually in the particular, inasmuch as the essence of the particular may be considered in itself and abstractly. But, once the direct universal is apprehended, nothing prevents the intellect from adding to it the consideration of its relation to individuals, and thus arriving at the reflex universal.
37. To perceive the direct universal, mere abstraction by the intellect is sufficient; to form the reflex universal, the intellect must regard the essence as common to all the individuals possessing it. -- The consideration of the essence in itself involves no scrutiny as to whether it exists in one individual or in many individuals, whether it is real or ideal; for its perception, the intellect need only abstract it from the individual characteristics. But the reflex. universal contains a relation to individuals, and hence supposes a comparison by the intellect as well as abstraction.
38. The direct universal has a real existence in the thing perceived, but not in the manner in which it is perceived; the reflex universal as such has only an ideal existence. -- The essence apprehended by the intellect in the direct act exists really in the individuals, but not in the manner in which it is apprehended, that is, as abstracted from individual characteristics; evidently this abstraction is the work of the intellect, In the same way, the color of fruit is really in the fruit, but any consideration of it apart from the taste is due to the sight, which perceives color, and not taste. The reflex universal as such exists solely in the intellect, since it is universal only in virtue of the reflection of the intellect, and this mental operation can be exercised on the ideas of things, but not on the things themselves.
ART II. -- DIFFERENT OPINIONS ON THE NATURE OF UNIVERSALS.
39. The different opinions on the nature of universals may be reduced to three principal heads: Nominalism, Conceptualism, and Realism. -- It may be said that there have been as many different opinions on the nature of universals as there have been diverse systems on the origin and nature of ideas. All, however, may be reduced to the three opinions which gave rise to so much controversy in the middle ages.
The Nominalists, headed by Roscelin (d. 1122), and later by Ockham, the Invincible Doctor (d. 1347), maintained that universals were mere words; the Conceptualists, represented by Abélard (1079-1142), made universals merely conceptions; the Realists, however, gave to universals a real existence outside the mind. But of this last class some confined themselves to attributing reality to the essence perceived, in so far only as it is individual and concrete; these are the Moderate Realists, and have St. Thomas of Aquin (1225-1274) at their head. Others attributed reality to the essence as qualified by the very abstraction and universality under which it is regarded; these are the Ultra-Realists, such as William of Champeaux (d. 1121) and Joannes Scotus Erigena (d. 875). Thus, according to the Moderate Realists, the essence "man" really exists outside the mind in individual men, but not with that abstraction and universality under which the mind considers it; according to the Ultra-Realists, the essence "man" really exists in an abstract and universal manner.
Nominalism is manifestly the negation of all science and the fruitful parent of Scepticism; Conceptualism being nothing more than disguised Nominalism, leads to the same consequences; Ultra-Realism directly produces Pantheism. With Nominalism are connected the systems of Epicurus, Locke, Condillac, Hume (1711-1776), in a word, of Materialists, Sensists, and the Empiricists of the Scotch school. With Conceptualism the systems of the Stoics of old, of Descartes, Berkeley (1684-1753), Kant, and all the Idealists, stand in close relation. Finally, to Ultra-Realism belong the systems of Plato, Averroës, Malebranche, Hegel, and Gioberti, that is, the systems of the Ontologists and Pantheists.
The chief exponents of Nominalism and Conceptualism in our day are respectively John S. Mill (1806-1878) and Sir W. Hamilton (1788-1856). The latter explains apprehension or the formation of ideas as a bundling together of attributes not the same, but called similar, because, though observed in different individuals of the same class, they produce in us the same effect as when first observed in a particular individual of that class. From this it follows in the teaching of Sir W. Hamilton: 1. That ideas convey not absolute but relative truth, relative, namely, to the object first perceived; hence certitude is impossible; 2. Ideas are merely subjective. Here the door is opened to Scepticism.
John Stuart Mill, following Dugald Stewart (1758-1828), holds that the ideas of individuals belonging to the same class have nothing in common but the name. When the mind perceives an object, in virtue of its power of abstraction, it fixes its attention on certain qualities to the exclusion of others, the qualities selected being those that are recalled to us whenever we perceive another object belonging to the same class. Hence It follows: 1. That the idea has no foundation in reality, and all positive belief in the most fundamental truths of religion is undermined; 2. That the common name is merely a convenience, and does not express any corresponding idea. Hence this system is even more radically sceptical than the other.
From these principles it is easy to gather the doctrines of Modern Conceptualists and Nominalists with regard to Universals.