REALITY AND EXISTENCE
In Chap. I of the Nature of Existence McTaggart asserts that reality is an indefinable quality which belongs to everything that is. Existence, he says, appears prima facie to be a specific modification of the generic quality reality.
Reality is not a quality which admits of degree, as some have thought. This mistake has arisen partly through confusing reality with power, which of course has degrees. Another factor in causing the mistake is the following. A certain predicate Q may misrepresent the nature of a certain subject S less than a certain other predicate P does. If so, there is a meaning in saying that the proposition S is Q is "truer than" the proposition S is P. People are liable to jump from this to saying that an S which is Q would be "more real than" an S which is P. If this is meant to be anything more than a verbal restatement of the fact that Q misrepresents the nature of S less than P does, it is false. If S be not Q and be not P, then neither an S which is Q nor an S which is P is real at all.
Again, McTaggart says that it is nonsense to regard reality as a relational property which essentially involves a relation to some universe of discourse. It is never literally true that a term is real in one universe of discourse and unreal in another, though such phraseology may be significant and true if interpreted metaphorically.
Whilst these negative statements of McTaggart's are true and important, his doctrine that reality is a generic quality and that existence is a specific modification of it is, I think, quite certainly false. McTaggart remarks in § 2 that, although reality is a quality which belongs to everything that is, yet not all predications of unreality are self-contradictory. Some are in fact true. It is true that Apollo is unreal, that mermaids are unreal, and that the rational number whose square is equal to 2 is unreal. But he does not explain how predications of unreality fail to be self-contradictory; and it seems to me that, on his theory, they all would be self-contradictory. Take, for example, the judgment that Apollo is unreal. This must be about something, and, on McTaggart's view, it must deny that the something which it is about has the quality of reality. But equally, on his view, that which the judgment is about, whatever that may be, has the quality of reality, since this belongs to all that is. And so the judgment is self-contradictory in the sense that it denies of its subject a quality which must be present in every subject.
The fact is, of course, that we are misled into thinking that reality is a quality, and that judgments which assert or deny reality are like those which assert or deny redness, by a likeness of verbal form which conceals a profound difference of logical structure. The sentence "Lions are real" has the same verbal form as the sentence "Lions are yellow", and the sentence "Mermaids are not real" has the same verbal form as the sentence "Lions are not herbivorous". But the judgments which are expressed respectively by "Lions are real " and by " Lions are yellow" are quite different in nature. The first is about the defining characteristic of the class lion, and it asserts of it that it has instances. The second is about the instances of this defining characteristic, and it asserts that they have yellowness. Similar remarks apply to the negative judgments which are expressed respectively by the sentences "Mermaids are not real" and "Lions are not herbivorous". The first is about the defining characteristic of the class mermaid, and it denies of it that it has instances. It is in fact equivalent to the statement that nothing has a woman's body and a fish's tail. The second is about the instances of the lion-characteristic, and it denies of them that they are herbivorous.
Thus there is no such quality as "reality"; though there is the characteristic of having instances, and this belongs to some characteristics and not to others.
Since there is no such quality as "reality", existence cannot be a specific modification of the generic quality reality, as McTaggart alleges. Nevertheless, existence may be a genuine quality which belongs to some entities and not to others. Given a certain definition or description, we might be able to say that, if anything answered to it, this entity would exist. Given a certain other definition or description, we might be able to say that, if anything answered to it, this entity would not exist but would subsist. Thus, for example, if the characteristic of being wholly evil had an instance, this instance would certainly exist and not subsist. And, if the characteristic of being a rational number whose square is equal to 2 had an instance, this instance would certainty subsist and not exist.
I think it will be useful to introduce the terms "existend" and "subsistend" at this point. The statement that x is existend means that, if there were any instance of the definition or description of x, this instance would exist. A similar definition, mutatis mutandis, could be given of the statement that x is subsistend. When, and only when, we wish to convey the belief, not only that x is existend, but also that there is such a thing as x, we say that x exists or is existent. Similar remarks apply, mutatis mutandis, to x subsists" or "x is subsistent". Thus, for example, I should say that both lions and phoenixes are existend, that lions exist or are existent, and that phoenixes do not exist or are not existent. And I should say that both the rational number whose square is equal to 4 and the rational number whose square is equal to 2 are subsistend, that the former subsists or is subsistent, and that the latter does not subsist or is not subsistent.
The characteristics existend and subsistend, though mutually exclusive and collectively exhaustive, do not seem to me to be determinates under any higher determinable. As we have seen, they quite certainly cannot be regarded as determinates under a determinable quality of which "reality" is the name.
In Chap. IV of the Nature of Existence McTaggart discusses the question whether anything exists. According to him it is neither self-evident that something exists, nor is the fact that something exists deducible from any premises which are self-evident. Nevertheless, it is quite certain that something does exist, and anyone who doubted it or denied it could be shown how to convince himself that his doubt is groundless or that his denial is mistaken. The argument is as follows.
If a man doubts or denies that something exists, then there is certainly something which he describes, rightly or wrongly, as his doubt or denial that something exists. And so the fact that there is this doubt or denial is inconsistent with the doubt being justified and with the denial being true.
This argument has, in my opinion, a suppressed premise. I agree that the fact that there is a doubt or a denial entails that there is something. But it does not by itself entail that this something is existent, as McTaggart claims. A sceptic about existence might admit that there is something which he describes, rightly or wrongly, as his doubt or denial that something exists. But he might then add: "This something certainly appears to me on inspection to be, or to contain, an existent. But might this not be an illusion? Is it not possible that, although it appears to me to be or to contain an existent, it is really a subsistent which does not contain or involve any existent?" I do not see how this could be refuted except in one of two ways.
There remains one other point that is worth mentioning. Granted that the fact that there is something which exists cannot be seen by us to be necessary, either by direct inspection or by deduction from other facts which we can see to be necessary, three alternatives remain open.
Now it is not clear which of these alternatives McTaggart would have held, or whether he would have said that he could not decide between them. I suspect, however, that at this point in his work he would have claimed to hold the second, if the question had been put to him. A person who accepted the Ontological Argument would hold that it is, and can be seen by human beings to be, necessary that there is something which exists. For he thinks that he can prove that there must be something answering to the description "most perfect being", and that existence is involved in this description. St Thomas Aquinas, I think, would have held that it is necessary that there is something that exists, but that only God or angels can see the necessity of this fact. Men can see only that the existence of God is a necessary consequence of certain facts which, so far as we can see, are contingent, e.g, the fact that there is motion and qualitative change.