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 of 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. (§ 10 ¶ 1)

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. (§ 10 ¶ 2)

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. (§ 10 ¶ 3)

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 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: (§ 11 ¶ 1)

(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, then it is impossible either to prove that any other definition is wrong or even to deny such definition. (§ 11 ¶ 2)

(2) The other alternative will scarcely be more welcome. It is that the discussion is after all a verbal one. When A says Good means pleasant and B says Good means desired, they may merely wish to assert that most people have used the word for what is pleasant and for what is desired respectively. And this is quite an interesting subject for discussion: only it is not a whit more an ethical discussion than the last was. Nor do I think that any exponent of naturalistic Ethics would be willing to allow that this was all he meant. They are all so anxious to persuade us that what they call the good is what we really ought to do. Do, pray, act so, because the word good is generally used to denote actions of this nature: such, on this view, would be the substance of their teaching. And in so far as they tell us how we ought to act, their teaching is truly ethical, as they mean it to be. But how perfectly absurd is the reason they would give for it! You are to do this, because most people use a certain word to denote conduct such as this. You are to say the thing which is not, because most people call it lying. That is an argument just as good!—My dear sirs, what we want to know from you as ethical teachers, is not how people use a word; it is not even, what kind of actions they approve, which the use of this word good may certainly imply: what we want to know is simply what is good. We may indeed agree that what most people do think good, is actually so; we shall at all events be glad to know their opinions: but when we say that their opinions about what is good, we do mean what we say; we do not care whether they call that thing horse or table or chair, gut or bon or ἀγαθός; we want to know what it is that they so call. When they say Pleasure is good, we cannot believe that they merely mean Pleasure is pleasure and nothing more than that. (§ 11 ¶ 3)

Suppose a man says I am pleased; and suppose it is not a lie or a mistake but the truth. Well, if it is true, what does that mean? It means that his mind, a certain definite mind, distinguished by certain definite marks from all others has at this moment a certain definite feeling called pleasure. Pleased means nothing but having pleasure, and though we may be more pleased or less pleased, and even, we may admit for the present, have one or another kind of pleasure; yet in so far as it is pleasure we have, whether there be more or less of it, and whether it be of one kind or another, what we have is one definite thing, absolutely indefinable, some one thing that is the same in all the various degrees and in all the various kinds of it that there may be. We may be able to say how it is related to other things: that, for example, it is in the mind, that it causes desire, that we are conscious of it, etc., etc. We can, I say, describe its relations to other things, but define it we can not. And if anybody tried to define pleasure for us as being any other natural object; if anybody were to say, for instance, that pleasure means the sensation of red, and were to proceed to deduce from that that pleasure is a colour, we should be entitled to laugh at him and to distrust his future statements about pleasure. Well, that would be the same fallacy which I have called the naturalistic fallacy. That pleased does not mean having the sensation of red, or anything else whatever, does not prevent us from understanding what it does mean. It is enough for us to know that pleased does mean having the sensation of pleasure, and though pleasure is absolutely indefinable, though pleasure is pleasure and nothing else whatever, yet we feel no difficulty in saying that we are pleased. The reason is, of course, that when I say I am pleased, I do not mean that I am the same thing as having pleasure. And similarly no difficulty need be found in my saying that pleasure is good and yet not meaning that pleasure is the same thing as good, that pleasure means good, and that good means pleasure. If I were to imagine that when I said I am pleased, I meant that I was exactly the same thing as pleased, I should not indeed call that a naturalistic fallacy, although it would be the same fallacy as I have called naturalistic with reference to Ethics. The reason of this is obvious enough. When a man confuses two natural objects with one another, defining the one by the other, if for instance, he confuses himself, who is one natural object, with pleased or with pleasure which are others, then there is no reason to call the fallacy naturalistic. But if he confuses good, which is not in the same sense a natural object, with any natural object whatever, then there is a reason for calling that a naturalistic fallacy; its being made with regard to good marks it as something quite specific, and this specific mistake deserves a name because it is so common. As for the reasons why good is not to be considered a natural object, they may be reserved for discussion in another place. But, for the present, it is sufficient to notice this: Even if it were a natural object, that would not alter the nature of the fallacy nor diminish its importance one whit. All that I have said about it would remain quite equally true: only the name which I have called it would not be so appropriate as I think it is. And I do not care about the name: what I do care about is the fallacy. It does not matter what we call it, provided we recognise it when we meet with it. It is to be met with in almost every book on Ethics; and yet it is not recognised: and that is why it is necessary to multiply illustrations of it, and convenient to give it a name. It is a very simple fallacy indeed. When we say that an orange is yellow, we do not think our statement binds us to hold that orange means nothing else than yellow, or that nothing can be yellow but an orange. Supposing the orange is also sweet! Does that bind us to say that sweet is exactly the same thing as yellow, that sweet must be defined as yellow? And supposing it be recognised that yellow just means yellow and nothing else whatever, does that make it any more difficult to hold that oranges are yellow? Most certainly it does not: on the contrary, it would be absolutely meaningless to say that oranges were yellow unless yellow did in the end mean just yellow and nothing else whatever—unless it was absolutely indefinable. We should not get any very clear notion about things, which are yellow—we should not get very far with our science, if we were bound to hold that everything which was yellow, meant exactly the same thing as yellow. We should find we had to hold that an orange was exactly the same thing as a stool, a piece of paper, a lemon, anything you like. We could prove any number of absurdities; but should we be the nearer to the truth? Why, then, should it be different with good? Why, if good is good and indefinable, should I be held to deny that pleasure is good? Is there any difficulty in holding both to be true at once? On the contrary, there is no meaning in saying that pleasure is good, unless good is something different from pleasure. It is absolutely useless, so far as Ethics is concerned, to prove, as Mr Spencer tries to do, that increase of pleasure coincides with increase of life, unless good means something different from either life or pleasure. He might just as well try to prove that an orange is yellow by shewing that it is always wrapped up in paper. (§ 12 ¶ 1)

In fact, if it is not the case that good denotes something simple and indefinable, only two alternatives are possible: either it is a complex, a given whole, about the correct analysis of which there could be disagreement; or else it means nothing at all, and there is no such subject as Ethics. In general, however, ethical philosophers have attempted to define good, without recognising what such an attempt must mean. They actually use arguments which involve one or both of the absurdities considered in § 11. We are, therefore, justified in concluding that the attempt to define good is chiefly due to want of clearness as to the possible nature of definition. There are, in fact, only two serious alternatives to be considered, in order to establish the conclusion that good does denote a simple and indefinable notion. It might possibly denote a complex, as horse does; or it might have no meaning at all. Neither of these possibilities has, however, been clearly conceived and seriously maintained, as such, by those who presume to define good; and both may be dismissed by a simple appeal to facts. (§ 13 ¶ 1)

(1) The hypothesis that disagreement about the meaning of good is disagreement with regard to the correct analysis of a given whole, may be most plainly seen to be incorrect by consideration of the fact that, whatever definition may be offered, it may always, be asked, with significance, of the complex so defined, whether it is itself good. To take, for instance, one of the more plausible, because one of the more complicated of such proposed definitions, it may easily be thought, at first sight, that to be good may mean to be that which we desire to desire. Thus if we apply this definition to a particular instance and say When we think that A is good, we are thinking that A is one of the things which we desire to desire, our proposition may seem quite plausible. But, if we carry the investigation further, and ask ourselves Is it good to desire to desire A? it is apparent, on a little reflection, that this question is itself as intelligible, as the original question, Is A good?—that we are, in fact, now asking for exactly the same information about the desire to desire A, for which we formerly asked with regard to A itself. But it is also apparent that the meaning of this second question cannot be correctly analysed into Is the desire to desire A one of the things which we desire to desire?: we have not before our minds anything so complicated as the question Do we desire to desire to desire to desire A? Moreover any one can easily convince himself by inspection that the predicate of this proposition—good—is positively different from notion of desiring to desire which enters into its subject: That we should desire to desire A is good is not merely equivalent to That A should be good is good. It may indeed be true that what we desire to desire is always good; perhaps, even the converse may be true: but it is very doubtful whether this is the case, and the mere fact that we understand very well what is meant by doubting it, shews clearly that we have to different notions before our mind. (§ 13 ¶ 2)

(2) And the same consideration is sufficient to dismiss the hypothesis that good has no meaning whatsoever. It is very natural to make the mistake of supposing that what is universally true is of such a nature that its negation would be self-contradictory: the importance which has been assigned to analytic propositions in the history of philosophy shews how easy such a mistake is. And thus it is very easy to conclude that what seems to be a universal ethical principle is in fact an identical proposition; that, if, for example, whatever is called good seems to be pleasant, the proposition Pleasure is the good does not assert a connection between two different notions, but involves only one, that of pleasure, which is easily recognised as a distinct entity. But whoever will attentively consider with himself what is actually before his mind when he asks the question Is pleasure (or whatever it may be) after all good? can easily satisfy himself that he is not merely wondering whether pleasure is pleasant. And if he will try this experiment with each suggested definition in succession, he may become expert enough to recognise that in every case he has before his mind a unique object, with regard to the connection of which with any other object, a distinct question may be asked. Every one does in fact understand the question Is this good? When he thinks of it, his state of mind is different from what it would be, were he asked Is this pleasant, or desired, or approved? It has a distinct meaning for him, even though he may not recognise in what respect it is distinct. Whenever he thinks of intrinsic value, or intrinsic worth, or says that a thing ought to exist, he has before his mind the unique object—the unique property of things—that I mean by good. Everybody is constantly aware of this notion, although he may never become aware at all that it is different from other notions of which he is also aware. But, for correct ethical reasoning, it is extremely important that he should become aware of this fact; and as soon as the nature of the problem is closely understood, there should be little difficulty in advancing so far in analysis. (§ 13 ¶ 3)