INDIVIDTTAL
763
INDIVIDUAL
distinguished from all other beings, and especially
from other beings of the same species? One obvious
answer is given in the enumeration of such differences
as those of place, time, figure. But these are merely
extrinsic relations. Nor is perfect identity, even in
place, between two beings wholly inconceivaljle.
These extrinsic differences, in fact, presuppose intrinsic
differences. Two things must first differ in relation
to each other before they can differ in relation to a
third or extrinsic thing, such as space. Hence the
question which exercised the philosophical schools
referred especially to intrinsic difference. What is
the intrinsic principle of individuation by which one
being is distinct from another? In the Aristotelean
theory the corporeal objects around us are composite
beings ultimately constituted of two principles, one
passive and determinalile (matter) , the other active and
determining (form). The latter gives the being its
specific nature. The former is the ground of divisi-
bility and multiplicity; and this is for .\ristotle the
source of individuation. The question, however, re-
ceived much fuller development and discussion in the
Middle Ages, and we find a number of different replies
advanced by different philosophers.
According to St. Thomas, who developed the Aristotelean doctrine, the form, in so far as corporeal beings are concerned, gives specific unity and deter- minateness to the thing. But many individuals can exist in the same species; it is thus the specific form which furnishes the common basis for the universal idea. The form, therefore, cannot be the source of individuation, since it itself needs a principle by which it may be individuated. This principle, the ratio distindionis, the cause of difference between one individual and another, must be sought in the limit- ing principle which receives the form, and is the ground of divisibility and multiplicity — the matter. This teacliing of St. Thomas is made clearer by his doctrine concerning the nature of intelligentiae, or angels. They are pure forms devoid of any material element. Consequently the angelic nature contains no ground within it for multiplication; there can be only one in a species. Unlike men, who differ numeri- cally in the same species, the several angels must differ specifically. In composite corporeal beings, the matter is the principle of limitation and individua- tion. But St. Thomas insists that it is materia signata quantitate. How precisely this is to be interpreted has been much disputed by the commentators. Ca- jetan understands materia here as the foundation and root of quantity, others as matter endowed with actual quantity. (For different views see especially Suarez, "Disp. Metaph.", V.) On the other hand, Durandus and .\verrhoes taught that form was the internal principle of individuation conferring numeri- cal unity on the subject which it constitutes. Scotus tends partly towards this view, adding, however, a further entity to the form proper. Matter, he argues, cannot be the principle of individuation, because it is essentially universal. Hence the principle must lie in the form, not, however, simply as universal nature, but with a particular formality added. This further difference determining the species down to the in- dividual, he calls by the name, hircceitas (thisness).
The Nominalist teaching on universals led its ad- vocates to a solution of this question quite different from that of either St. Thomas or Scotus. According to them the universal has no existence outside of the mind, no foundation in external nature. Every reality, as such, is individual. As Occam urged: "Quaelibet res singularis seipsa est singularis, unum per se"; hence dispute about an internal principle of individuation is futile. If we speak of a cause of individuation we can only intelligibly allude to the creative will, or efficient cause, which gave existence to the thing. Others, however, who are very far from being Nominalists, also hold this view. Indeed
it is adopted by Suarez himself, who maintains:
" Omnem substantiam singularem nee alio indigere
individuationis principio prajter suam entitatem, vel
prseter principia intrinseca quibus ejus entitas con-
stat" (each singular substance is individualized by
its own entity, and requires no other principle for its
individuation). This solution he holds to be the
clearest of all — omnium clarissimam. (There is an
exhaustive discussion of the whole question with
abundant references to all the chief medieval philoso-
phers, scholastic and Arabic, in Suarez, "Disp. Meta-
phys.", V.) A view akin to that of Suarez was
advocated by Leibniz in his treatise " De principio
individui".
Nowadays interest in the more subtile phases of the old metaphysical problem has decluied, but a more fundamental question, raised by the theory of Monism, has come to the fore. Instead of the question, " How, precisely, do individual beings of the same species differ from each other?" we are asked, "Are there any truly individual beings in the universe at all? Or are the seemingly distinct, independent objects of the world around us, including our fellow-men, merely modes, phases, or aspects of the Absolute, of the In- finite, of the underlying substratum or ground of all things?" For Spinoza "omnis determinatio est ne- gatio" — every individual determination is merely a negation, a limitation of the universal, and nothing has positive existence except the one infinite sub- stance, of which the seemingly distinct, individual, finite beings are merely parts or modes. This denial of true individuality to all finite beings is the doctrine of Monism which, whether in an idealistic or material- istic form, has acquired steadily increasing influence since the time of Spinoza, and especially during the last century. Consequently the question of individ- uality is now shifted to that of the personality of human beings; for, obviously, it is in regard to them that the question becomes of most interest, and at the same time most capable of decisive proof.
Psychology. — It is only of persons that individ- uality can in the strict sense be predicated. A person is usually defined as an individual substance of a rational nature. It implies independence or existence in itself. Neither animals nor lifeless mat- ter are persons, and so they do not possess this complete indi\-i(luality. The strongest proof of the reality of human beings in the world around us rests therefore on the evidence for human personality, and for each of us ultimately on the proof of our own personality. My conviction of my personality and individual existence is the outcome of my experience. Rational self-consciousness combined with memory assure me of the aljiding identity of my own being. That I am the same person who underwent a danger- ous illness long ago as a child, who aci(uired a knowl- edge of certain branches of learning during my youth, who ha\-e recently gone through some particular ex- periences, and who am now engageii in writing these sentences, is affirmed with irresistil)le clearness and force by my intellect. Further, I have been conscious of exercising free volition and determining my own actions. I have found myself acted upon by certain impulses, and I have resisted or freely yielded to them. I have reaUzed in and after such acts that they were mine, and that I was responsible for them. I have had it constantly impressed upon me that there is an external world which no effort of my will can annihi- late. My reason assures me of my separateness from it and of its independence of me. If any truth is certain to me, then it mu.st be that of my own abiding existence as a rational person responsible for my deliberate acts. But this implies my own individual- ity — the unity of my being together with the inde- pendence or separateness of my existence.
The self-conscious ego is thus the perfect type of the individual being. But if I assert my own existence
