George Edward Moore: Principia Ethica

§ 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 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.

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.

§13. 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. 

(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.

(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.