If only one of the factors is seen to be capable of existing without the other, and the latter to be such that it could not actually exist except as united with the former, so that the separability is not mutual, the distinction is regarded still as real, but only as a minor or modal distinction. Such, for instance, is the distinction between a body and its location, or its state of rest or motion: and, in general, the distinction between a substance and what are called its accidental modes or modal accidents. The distinction is regarded as real because reflection is held to assure us that it is in the reality itself independently of the mind, and not merely imposed by the mind on the reality because of some ground or reason in the reality. It is called a modal distinction rather than an absolute real distinction because those accidental modes of a substance do not seem to have of themselves sufficient reality to warrant our calling them “things” or “realities,” but rather merely “modes” or “determinations” of things or realities. It is significant, as throwing light on the relation of the virtual to the real distinction, that some authors call the modal distinction not a real distinction but a “distinctio media,” i.e. intermediate between a real and a logical distinction; and that the question whether it should be called simply a real distinction, or “intermediate” between a real and a logical distinction is regarded by some as “a purely verbal question.”[159] We shall recur to the modal distinction later ([68]).
In the third place it must be noted that separability in the sense explained, even non-mutual, is not regarded as the only index to a real distinction. In other words, certain distinctions are held by some to be real even though this test of separability does not apply. For instance, it is commonly held that not merely in man but in all corporeal individuals the formative and the determinable principle of the nature or substance, the forma substantialis and the materia prima, are really distinct, although it is admitted that, apart from the case of the human soul, neither can actually exist except in union with the other. What is held [pg 151] in regard to accidental modes is also applied to these essential principles of the corporeal substance: viz. that there is here a special reason why such principles cannot actually exist in isolation. Of their very nature they are held to be such that they cannot be actualized or actually exist in isolation, but only in union. But this fact, it is contended, does not prove that the principles in question are merely mentally distinct aspects of one reality: the fact that they cannot actually exist as such separately does not prove that they are not really separable; and it is contended that they are really and actually separated whenever an individual corporeal substance undergoes substantial change.
This, then, raises once more the question: What sort of “separation” or “separability” is the test of a real distinction? Is it separateness in and for sense perception, or separateness in and for intellectual thought? The former is certainly the fundamental index of the real distinction; for all our knowledge of reality originates in sense experience, and separateness in time and space, which marks its data, is the key to our knowledge of reality as a manifold of really distinct individual beings; and when we infer from sense-experience the actual existence of a spiritual domain of reality we can conceive its “individuals” only after the analogy of the corporeal individuals of our immediate sense experience. Scholastic philosophers, following Aristotle, have always taken the manifoldness of reality, i.e. its presentation in sense experience in the form of “individuals,” of “this” and “that,” “τοδὲ τι,” “hoc aliquid,” as an unquestioned and unquestionable real datum. Not that they naïvely assumed everything perceived by the senses as an individual, in time and space, to be really an individual: they realized that what is perceived by sense as one limited continuum, occupying a definite portion of space, may be in reality an aggregate of many individuals; and they recognized the need of scrutinizing and analysing those apparent individuals in order to test their real individuality; but they held, and rightly, that sense experience does present to us some data that are unmistakably real individuals—individual men, for instance. Next, they saw that intellectual thought, by analysing sense experience, amasses an ever-growing multitude of abstract and conceptually distinct thought-objects, which it utilizes as predicates for the interpretation of this sense experience. These thought-objects intellect can unite or separate; can in some cases positively see to be mutually compatible or incompatible; can form into ideal or possible complexes. But whether or not the conceptually distinct, though mutually compatible, thought-objects forming any such complex, will be also really distinct from one another, is a question which evidently cannot arise until such a complex is considered as an actual or possible individual being: for it is the individual only that exists or can exist. They will be really distinct when found actualized in distinct individuals. Even the conceptually one and self-identical abstract thought-object will be really distinct from itself when embodied in distinct individuals; the one single abstract thought-object, “humanity,” “human nature,” is really distinct from itself in John and in James; the humanity of John is really other than the humanity of James.
Of course, if conceptually distinct thought-objects are seen to be mutually incompatible they cannot be found realized except in really distinct individuals: the union of them is only an ens rationis. Again it may be that the intellect is unable to pronounce positively as to whether they are compatible or not ([18]): as to whether the complex forms a possible being or not. But when the intellect positively sees such thought-objects to be mutually compatible—by interpretation of, and inference from, its actual sense experience of them as embodied in individuals ([18])—and when, furthermore, it now finds a number of them co-existing in some one actual individual, the question recurs: How can it know whether they are really distinct from each other, though actually united to form one (essentially or accidentally composite) individual, or only conceptually distinct aspects of one (simple) individual [[27 (b)]]?
This, as we have seen already, is the case for which it is really difficult to find a satisfactory test: and hence the different views to be found among scholastic philosophers as to the nature of the distinctions which the mind makes or discovers within the individual. The difficulty is this. The conceptual distinction between compatible thought-objects is not a proof of real distinction when these thought-objects are found united in one individual of sense experience, as e.g. animality and rationality in man; and the only distinction given to us by sense experience, at least directly and immediately, as undoubtedly real, is the distinction between corporeal individuals existing apart in space or time, as e.g. between man and man. How then, can we show that any distinctions within the individual are real?
Well, we have seen that certain entities, which are objects of sense or of thought, or of both, can disappear from the individual without the residue thereby perishing or ceasing to exist actually as an individual: the human soul survives, as an actual individual reality, after its separation from the material principle with which it formed the individual man; the individual man persists while the accidental modes that affect him disappear. In such cases as these, intellect, interpreting sense experience and reasoning from it, places a real distinction, in the composite individual, between the factors that can continue to exist without others, and these latter. In doing so it is apparently applying the analogy of the typical real distinction—that between one individual and another. The factor, or group of factors, which can continue to exist actually after the separation of the others, is an individual: and what were separated from it were apparently real entities, though they may have perished by the actual separation. But on what ground is the distinction between the material principle and the vital principle of a plant or an animal, for example, regarded as real? Again on the ground furnished by the analogy of the distinction between individuals of sense experience. Note that it is not between the material and the vital principles as objects of abstract thought, i.e. between the materiality and the vitality of the plant or the animal, that a real distinction is claimed: these are regarded only as conceptually distinct aspects of the plant or the animal; nor is it admitted that because one of these thought-objects is found embodied elsewhere in nature without the other—materiality without vitality in the inorganic universe—we can therefore conclude that they are really distinct in the plant or the animal. No; it is between the two principles conceived as coexisting and united in the concrete individual that the real distinction is claimed. And it is held to be [pg 153] a real distinction because substantial change in corporeal things, i.e. corruption and generation of individual corporeal substances, is held to be real. If it is real there is a real separation of essential factors when the individual perishes. And the factors continue to be real, as potential principles of other individuals, when any individual corporeal substance perishes. Each principle may not continue to exist actually as such in isolation from the other—though some scholastics hold that, absolutely speaking, they could be conserved apart, as actual entities, by the Author of Nature. But they can actually exist as essential principles of other actual individuals: they are real potentialities, which become actual in other individuals. Thus we see that they are conceived throughout after the analogy of the individual. Those who hold that, absolutely speaking, the material principle as such, materia prima, could actually exist in isolation from any formative principle, should apparently admit that in such a case it would be an individual reality.
39. Some Questionable Distinctions. The Scotist Distinction.—The difficulty of discriminating between the virtual and the real distinction in an individual has given rise to the conception of distinctions which some maintain to be real, others to be less than real. The virtual distinction, as we have hitherto understood it, may be described as extrinsic inasmuch as it arises in the individual only when we consider the latter under different aspects, or in different relations to things extrinsic to it. By regarding an individual under different aspects—e.g. a man under the aspects of animality and rationality—we can predicate contradictory attributes of the individual, e.g. of a man that “he is similar to a horse,” and that “he is not similar to a horse”. Now it is maintained by some that although independently of the consideration of the mind the grounds of these contradictory predications are not actually distinct in the individual, nevertheless even before such consideration the individual has a real intrinsic capacity to have these contradictory predicates affirmed of him: they can be affirmed of him not merely when he is regarded, and because he is regarded, under conceptually different aspects, but because these principles, “animality” and “rationality,” are already really in him not merely as aspects but as distinct capacities, as potentially distinct principles of contradictory predications.
The virtual distinction, understood in this way, is described as intrinsic. It is rejected by some on the ground that, at least in its application to finite realities, it involves a violation of the principle of contradiction: it seems to imply that one and the same individual has in itself absolutely (and not merely as considered [pg 154] under different aspects and relations) the capacity to verify of itself contradictory predicates.
Scotus and his followers go even farther than the advocates of this intrinsic virtual distinction by maintaining the existence of a distinction which on the one hand they hold to be less than real because it is not between “thing and thing,” and on the other hand to be more than logical or virtual, because it actually exists between the various thought-objects or “formalitates” (such, e.g. as animality and rationality) in the individual, independently of the analytic activity whereby the mind detects these in the latter. This distinction Scotists call a “formal distinction, actual on the part of the thing”—“distinctio formalis, actualis ex natura rei.” Hence the name “formalists” applied to Scotists, from their advocacy of this “Scotistic” distinction. It is, they explain, a distinction not between “things” (“res”) but between “formalities” (“formalitates”). By “thing” as opposed to “formality” they mean not merely the individual, but also any positive thought-object which, though it may not be capable of existing apart, can really appear in, or disappear from, a thing which can so exist: for instance, the essential factors of a really composite essence, its accidental modes, and its real relations. By “formality” they mean a positive thought-object which is absolutely inseparable from the thing in which it is apprehended, which cannot exist without the thing, nor the thing without it: for instance, all the metaphysical grades of being in an individual, such as substantiality, corporeity, life, animality, rationality, individuality, in an individual man. The distinction is called “formal” because it is between such “formalities”—each of which is the positive term of a separate concept of the individual. It is called “actual on the side of the thing” because it is claimed to be actually in the latter apart from our mental apprehension of the individual. What has chiefly influenced Scotists in claiming this distinction to be thus actually in the individual, independently of our mental activity, is the consideration that these metaphysical grades are grounds on which we can predicate contradictory attributes of the same individual, e.g. of an individual man that “he is similar to a horse” and that “he is not similar to a horse”: whence they infer that in order to avoid violation of the principle of contradiction, we must suppose these grounds to be actually distinct in the thing.
To this it is replied, firstly, that if such predications were truly contradictory we could avoid violation of the principle of contradiction only by inferring a real distinction—which Scotists deny to exist—between these grounds; secondly, that such predications are not truly contradictory inasmuch as “he is similar” really means “he is partially similar,” and “he is not similar” means “he is not completely similar”; therefore when we say that a man's rationality “is not the principle whereby he resembles a horse,” and his animality “is the principle whereby he resembles a horse,” we mean (a) that his rationality is not the principle of complete resemblance, though we know it is the principle of partial resemblance, inasmuch as we see it to be really identical with that which is the principle of partial resemblance, viz. his animality; and we mean (b) that his animality is the principle of his partial resemblance to a horse, not of total resemblance, for we know that the animality of a man is not perfectly similar to that of a horse, the former being really identical with rationality, the latter with irrationality. When, then, we predicate of one thing that “it is similar to some other thing,” and that “it is not similar to this other thing” we are not really predicating contradictories of the same thing; if we take the predicates as contradictories they are true of the same reality undoubtedly, but not under the same aspect. Scotists themselves admit that the real identity of these aspects involves no violation of the principle of contradiction; why, then, should these be held to be actually distinct formalities independently of the consideration of the mind? How can a distinction that is actual independently of the mind's analysis of the reality be other than real? Is not predication a work of the mind? And must not the conditions on which reality verifies the predication be determined by the mind? If, then, we see that in order to justify this predication—of “similar” and “not similar”—about any reality, it is merely necessary that the mind should apprehend this reality to be in its undivided unity equivalent to manifold grades of being or perfection which the mind itself can grasp as mentally distinct aspects, by distinct concepts, how can we be justified in supposing that these grades of being are not merely distinguishable, but actually distinct in the reality itself, independently of the mind?