Principia Ethica

by G. E. Moore

6. What, then, is good? How is good to be defined? Now, it may be thought that this is a verbal question. A definition does indeed often mean the expressing of one word’s meaning in other words. But this is not the sort of definition I am asking for. Such a definition can never be of ultimate importance in any study except lexicography. If I wanted that kind of definition I should have to consider in the first place how people generally used the word ‘good’; but my business is not with its proper usage, as established by custom. I should, indeed, be foolish, if I tried to use it for something which it did not usually denote: if, for instance, I were to announce that, whenever I used the word ‘good,’ I must be understood to be thinking of that object which is usually denoted by the word ‘table.’ I shall, therefore, use the word in the sense in which I think it is ordinarily used; but at the same time I am not anxious to discuss whether I am right in thinking that it is so used. My business is solely with that object or idea, which I hold, rightly or wrongly, that the word is generally used to stand for. What I want to discover is the nature of that object or idea, and about this I am extremely anxious to arrive at an agreement.

But, if we understand the question in this sense, my answer to it may seem a very disappointing one. If I am asked ‘What is good?’ my answer is that good is good, and that is the end of the matter. Or if I am asked ‘How is good to be defined?’ my answer is that it cannot be defined, and that is all I have to say about it. But disappointing as these answers may appear, they are of the very last importance. To readers who are familiar with philosophic terminology, I can express their importance by saying that they amount to this: That propositions about the good are all of them synthetic and never analytic; and that is plainly no trivial matter. And the same thing may be expressed more popularly, by saying that, if I am right, then nobody can foist upon us such an axiom as that ‘Pleasure is the only good’ or that ‘The good is the desired’ on the pretence that this is ‘the very meaning of the word.’

7. Let us, then, consider this position. My point is that ‘good’ is a simple notion, just as ‘yellow’ is a simple notion; that, just as you cannot, by any manner of means, explain to any one who does not already know it, what yellow is, so you cannot explain what good is. Definitions of the kind that I was asking for, definitions which describe the real nature of the object or notion denoted by a word, and which do not merely tell us what the word is used to mean, are only possible when the object or notion in question is something complex. You can give a definition of a horse, because a horse has many different properties and qualities, all of which you can enumerate. But when you have enumerated them all, when you have reduced a horse to his simplest terms, then you can no longer define those terms. They are simply something which you think of or perceive, and to any one who cannot think of or perceive them, you can never, by any definition, make their nature known. It may perhaps be objected to this that we are able to describe to others, objects which they have never seen or thought of. We can, for instance, make a man understand what a chimaera is, although he has never heard of one or seen one. You can tell him that it is an animal with a lioness’s head and body, with a goat’s head growing from the middle of its back, and with a snake in place of a tail. But here the object which you are describing is a complex object; it is entirely composed of parts, with which we are all perfectly familiar—a snake, a goat, a lioness; and we know, too, the manner in which those parts are to be put together, because we know what is meant by the middle of a lioness’s back, and where her tail is wont to grow. And so it is with all objects, not previously known, which we are able to define: they are all complex; all composed of parts, which may themselves, in the first instance, be capable of similar definition, but which must in the end be reducible to simplest parts, which can no longer be defined. But yellow and good, we say, are not complex: they are notions of that simple kind, out of which definitions are composed and with which the power of further defining ceases.

8. When we say, as Webster says, ‘The definition of horse is “A hoofed quadruped of the genus Equus,”’ we may, in fact, mean three different things. (1) We may mean merely: ‘When I say “horse,” you are to understand that I am talking about a hoofed quadruped of the genus Equus.’ This might be called the arbitrary verbal definition: and I do not mean that good is indefinable in that sense. (2) We may mean, as Webster ought to mean: ‘When most English people say “horse,” they mean a hoofed quadruped of the genus Equus.’ This may be called the verbal definition proper, and I do not say that good is indefinable in this sense either; for it is certainly possible to discover how people use a word: otherwise, we could never have known that ‘good’ may be translated by ‘gut’ in German and by ‘bon’ in French. But (3) we may, when we define horse, mean something much more important. We may mean that a certain object, which we all of us know, is composed in a certain manner: that it has four legs, a head, a heart, a liver, etc., etc., all of them arranged in definite relations to one another. It is in this sense that I deny good to be definable. I say that it is not composed of any parts, which we can substitute for it in our minds when we are thinking of it. We might think just as clearly and correctly about a horse, if we thought of all its parts and their arrangement instead of thinking of the whole: we could, I say, think how a horse differed from a donkey just as well, just as truly, in this way, as now we do, only not so easily; but there is nothing whatsoever which we could so substitute for good; and that is what I mean, when I say that good is indefinable.

9. But I am afraid I have still not removed the chief difficulty which may prevent acceptance of the proposition that good is indefinable. I do not mean to say that the good, that which is good, is thus indefinable; if I did think so, I should not be writing on Ethics, for my main object is to help towards discovering that definition. It is just because I think there will be less risk of error in our search for a definition of ‘the good,’ that I am now insisting that good is indefinable. I must try to explain the difference between these two. I suppose it may be granted that ‘good’ is an adjective. Well ‘the good,’ ‘that which is good,’ must therefore be the substantive to which the adjective ‘good’ will apply: it must be the whole of that to which the adjective will apply, and the adjective must always truly apply to it. But if it is that to which the adjective will apply, it must be something different from that adjective itself; and the whole of that something different, whatever it is, will be our definition of the good. Now it may be that this something will have other adjectives, beside ‘good,’ that will apply to it. It may be full of pleasure, for example; it may be intelligent: and if these two adjectives are really part of its definition, then it will certainly be true, that pleasure and intelligence are good. And many people appear to think that, if we say ‘Pleasure and intelligence are good,’ or if we say ‘Only pleasure and intelligence are good,’ we are defining ‘good.’ Well, I cannot deny that propositions of this nature may sometimes be called definitions; I do not know well enough how the word is generally used to decide upon this point. I only wish it to be understood that that is not what I mean when I say there is no possible definition of good, and that I shall not mean this if I use the word again. I do most fully believe that some true proposition of the form ‘Intelligence is good and intelligence alone is good’ can be found; if none could be found, our definition of the good would be impossible. As it is, I believe the good to be definable; and yet I still say that good itself is indefinable.

10. ‘Good,’ then, if we mean by it that quality which we assert to belong to a thing, when we say that the thing is good, is incapable of any definition, in the most important sense of that word. The most important sense of ‘definition’ is that in which a definition states what are the parts which invariably compose a certain whole; and in this sense ‘good’ has no definition because it is simple and has no parts. It is one of those innumerable objects of thought which are themselves incapable of definition, because they are the ultimate terms by reference to which whatever is capable of definition must be defined. That there must be an indefinite number of such terms is obvious, on reflection; since we cannot define anything except by an analysis, which, when carried as far as it will go, refers us to something, which is simply different from anything else, and which by that ultimate difference explains the peculiarity of the whole which we are defining: for every whole contains some parts which are common to other wholes also. There is, therefore, no intrinsic difficulty in the contention that ‘good’ denotes a simple and indefinable quality. There are many other instances of such qualities.

Consider yellow, for example. We may try to define it, by describing its physical equivalent; we may state what kind of light-vibrations must stimulate the normal eye, in order that we may perceive it. But a moment’s reflection is sufficient to shew that those light-vibrations are not themselves what we mean by yellow. They are not what we perceive. Indeed we should never have been able to discover their existence, unless we had first been struck by the patent difference of quality between the different colours. The most we can be entitled to say of those vibrations is that they are what corresponds in space to the yellow which we actually perceive.

Yet a mistake of this simple kind has commonly been made about ‘good.’ It may be true that all things which are good are also something else, just as it is true that all things which are yellow produce a certain kind of vibration in the light. And it is a fact, that Ethics aims at discovering what are those other properties belonging to all things which are good. But far too many philosophers have thought that when they named those other properties they were actually defining good; that these properties, in fact, were simply not ‘other,’ but absolutely and entirely the same with goodness. This view I propose to call the ‘naturalistic fallacy’ and of it I shall now endeavour to dispose.

11. Let us consider what it is such philosophers say. And first it is to be noticed that they do not agree among themselves. They not only say that they are right as to what good is, but they endeavour to prove that other people who say that it is something else, are wrong. One, for instance, will affirm that good is pleasure, another, perhaps, that good is that which is desired; and each of these will argue eagerly to prove that the other is wrong. But how is that possible? One of them says that good is nothing but the object of desire, and at the same time tries to prove that it is not pleasure. But from his first assertion, that good just means the object of desire, one of two things must follow as regards his proof:

(1) He may be trying to prove that the object of desire is not pleasure. But, if this be all, where is his Ethics? The position he is maintaining is merely a psychological one. Desire is something which occurs in our minds, and pleasure is something else which so occurs; and our would-be ethical philosopher is merely holding that the latter is not the object of the former. But what has that to do with the question in dispute? His opponent held the ethical proposition that pleasure was the good, and although he should prove a million times over the psychological proposition that pleasure is not the object of desire, he is no nearer proving his opponent to be wrong. The position is like this. One man says a triangle is a circle: another replies ‘A triangle is a straight line, and I will prove to you that I am right: for’ (this is the only argument) ‘a straight line is not a circle.’ ‘That is quite true,’ the other may reply; ‘but nevertheless a triangle is a circle, and you have said nothing whatever to prove the contrary. What is proved is that one of us is wrong, for we agree that a triangle cannot be both a straight line and a circle: but which is wrong, there can be no earthly means of proving, since you define triangle as straight line and I define it as circle.’—Well, that is one alternative which any naturalistic Ethics has to face; if good is defined as something else, it is then impossible either to prove that any other definition is wrong or even to deny such definition.