Such judgments can be only probable, never certain. Thus, both types of ethical judgment presuppose the notion of good but in ways not always clearly distinguished. The situation is complicated because various combinations of intrinsic and instrumental value and disvalue or indifference may occur. Obligatory acts may have no intrinsic value at all, and acts that are impossible and thus not obligatory may have great intrinsic goodness.

Things having this simple, unique quality of goodness also have other properties, and this fact has misled philosophers into what Moore terms “the naturalistic fallacy.” To take any other property, such as “pleasant” or “desired,” no matter how uniformly associated with good, as definitive of “good,” is to make this error. These other properties exist in space and time, and hence are in nature; on the other hand, good is nonnatural; it belongs to that class of objects and properties that are not included in the subject matter of the natural sciences. Thus, when someone insists that “good” means “pleasant,” or in the substantive sense, “pleasure,” the person is defining good in terms of a natural object or property; that this is fallacious may be seen by substituting for the meaningful question, “Is pleasure good?” the question implied by such a definition: “Is pleasure pleasant?” Clearly one does not mean the latter, Moore insists, or anything like it, and can by direct inspection see what one does mean—one is asking whether pleasure is qualified by an unanalyzable and unique property.

That one can have this notion of good before one’s mind shows that “good” is not meaningless. The idea that it names a complex that might be analyzed variously must be rejected because one can always ask about any proposed definition of good as complex, “Is X good?” and see that the subject and predicate were not identical. For example, suppose “good” were defined as “that which we desire to desire.” Although one might plausibly think that “Is A good?” means “Is A that which we desire to desire?,” one can again ask the intelligible question, “Is it good to desire to desire A?” However, substituting the proposed definition yields the absurdly complicated question, “Is the desire to desire A one of the things that we desire to desire?” Again, obviously this is not what one means, and direct inspection reveals the difference between the notions of good and desiring to desire. The only remaining alternative is that “good” is indefinable; it must be clear, however, that this condition applies only to what is meant by the adjective “good,” not to “the good”; were the latter incapable of definition and description, ethics would be pointless.

Moore calls attention to another source of great confusion, the neglect of what he calls the “principle of organic unities.” This is the paradoxical but most important truth that things good, bad, and indifferent in various degrees and relationships may constitute a whole in which the values of the whole and parts are not regularly proportionate. Thus, it is possible for a whole made up of indifferent or even bad parts to be good, or for one containing only good parts to be indifferent or bad, and in less extreme cases, for parts of only moderate worth to constitute wholes of great value.

Crime with punishment may make a whole better than one of these two evils without the other; awareness of something beautiful has great intrinsic goodness, but the beautiful object by itself has relatively little value, and consciousness may sometimes be indifferent or bad. The relationship of part to whole is not that of means to end, because the latter consists of separable terms, and on removal of a means, the same intrinsic value may remain in the end, which situation does not obtain for part and whole. Failure to understand the principle of organic unities causes erroneous estimation of the value of a whole as equal to that of the parts.

The foregoing principles and distinctions form the core of Moore’s ethics and underlie both his criticism of other views and the final elaboration of his own. He argues that naturalistic theories that identify good with natural properties must either restrict the sense of “nature” if they define “good” in terms of the natural, because in other respects, the evil is just as “natural” as the good, or else must select some special feature of nature for this purpose. In any case, the naturalistic fallacy occurs. Hedonism, the view that “pleasure alone is good as an end,” is by far the most common form of ethical naturalism, and it receives more detailed treatment. Hedonism is initially plausible, Moore concedes; it is difficult to distinguish being pleased by something from approving it, but we do sometimes disapprove the enjoyable, which shows that the predicate of a judgment of approbation is not synonymous with “pleasant.” However, most hedonists have fallen into the naturalistic fallacy. John Stuart Mill furnishes a classic example when he asserts that nothing but pleasure or happiness and the avoidance of pain are desirable as ends, and then equates “desirable” with “desired.” Actually Mill later describes other things as desired, such as virtue, money, or health; thus, he either contradicts his earlier statements or makes false ones in attempting to show that such things as virtue or money are parts of happiness. He thus obliterates his own distinction—and one on which Moore insists—between means and ends.

Moore writes that of the hedonists, only Henry Sidgwick recognized that “good” is unanalyzable and that the hedonistic doctrine that pleasure is the sole good as an end must rest on intuition or be self-evident. Moore here freely admits what others might regard as a serious limitation in the intuitionist method—that Sidgwick’s and his own intuitions conflict and that neither is able to prove hedonism true or false. However, this is disturbing primarily because of the disagreement rather than the lack of proof, Moore adds, since ultimate principles are necessarily incapable of demonstration. The best one can do is to be as clear as possible concerning what such intuited principles mean and how they relate to other beliefs already held; only thus can one convince an opponent of error. Mill rejected philosopher Jeremy Bentham’s view that the only measures of value in pleasure are quantitative, and he suggested that there are differences in kind; one learns these by consulting competent judges and discovering their preferences. However, if pleasure is really the only desirable end, differences in quality are irrelevant; thus, Sidgwick reverted to the simpler form of hedonism but specified that the ultimate end is related essentially to human existence. Moore submits reasons for rejecting Sidgwick’s intuitions. The first objection is that it is obvious that the most beautiful world imaginable would be preferable to the most ugly even if no human beings at all were there to contemplate either. It follows that things separable from human existence can be intrinsically good. However, pleasure cannot be good apart from human experience; it is clear that pleasure of which no one was conscious would not be an end for its own sake. Consciousness must be a part of the end, and the hedonistic principle is thus seen to be false: It is not pleasure alone but pleasure together with consciousness that is intrinsically good.

The importance of this conclusion lies in the method used to achieve it—that of completely isolating the proposed good and estimating its value apart from all related objects—for the same method shows that consciousness of pleasure is not the only good. Surely no one would think that a world consisting of nothing but consciousness of pleasure would be as good as one including other existents, and even if these were not intrinsically valuable, the latter world could be better as an organic unity. Similar methods of analysis refute other forms of hedonism—egoistic and utilitarian; Moore concludes that, at best, pleasure would be a criterion of good were pleasure and the good always concomitant, but he regards this as very doubtful and supposes that there is no criterion of good at all.

The chief remaining type of ethics Moore criticizes is what he calls “metaphysical ethics,” positing some proposition about a supersensible reality as the basis for ethical principles. He admits that the metaphysicians are right in thinking that some things that are are not natural objects, but wrong in concluding that therefore whatever does not exist in nature must exist elsewhere. Things such as truth, universals, numbers, and goodness do not exist at all. However, metaphysical ethicists such as the Stoics, Baruch Spinoza, and Immanuel Kant have tried to infer what is good from what is ultimately real and thus have committed a variant of the naturalistic fallacy, for whether the reality involved is natural or supernatural is irrelevant. To the second basic ethical question, “What kind of actions ought we to perform?” a supersensible reality might be relevant, but typical metaphysical systems have no bearing on practice. For example, if the sole good pertains to an eternal, perfect, Absolute Being, there is no way by which human action can enhance the goodness of this situation.

Perhaps the metaphysical ethicists have thus erred through failing to notice the ambiguity of the question, “What is good?,” which may refer either to good things or to goodness itself; this ambiguity accounts for the inconsistency between such propositions as that the only true reality is eternal and that its future realization is good, when what is meant is that something like—but not identical with—such a reality would be good. However, in this case it becomes clear that it is fallacious to define good as constituted by this reality. Although “X is good” is verbally similar to other propositions in which both subject and predicate stand for existents, it is actually radically different; of any two existents so related one may still ask, “Is this whole good?,” which again shows the uniqueness of the value predicate.

It is essential to remember that in answering the question as to what we ought to do once we know intuitively what things are good as ends, a different method must come into use. Because practical ethical judgments assert causal relations between actions and good or bad effects, the empirical method affording probability, never certainty, is indicated. Thus, Moore differs from traditional intuitionists both in his definition of “right” and in his account of how it is known. Right is not to be distinguished from the genuinely useful, and duty is “that action, which will cause more good to exist in the Universe than any possible alternative.” In practice, knowledge of right and duty is most limited, so we must consider as duties those acts that will usually yield better results than any others. Such limitations do not excuse individuals from following the general rules, but when the latter are lacking or irrelevant, attention should be redirected to the much neglected intrinsic values of the foreseeable effects. It follows, of course, that virtue, like duty, is a means rather than an end, contrary to the views of some Christian writers and even of Kant, who hold inconsistently that either virtue or good will is the sole good, but that it can be rewarded by something better.

It remains to state Moore’s conception of “the good,” or the ideal. He notes that he will try to describe the ideal merely as that which is intrinsically good in a high degree, not the best conceivable or the best possible. Its general description follows: “The best ideal we can construct will be that state of things that contains the greatest number of things having positive value, and that contains nothing evil or indifferent—provided that the presence of none of these goods, or the absence of things evil or indifferent, seems to diminish the value of the whole.” The method of discovering both the intrinsically valuable and its degrees of value is that previously mentioned: the method of isolation. It will show that “by far the most valuable things, which we know or can imagine, are certain states of consciousness, which may be roughly described as the pleasures of human intercourse and the enjoyment of beautiful objects.” Moore stresses the point that it is these wholes, rather than any constituents, that are the ideal ends.

In aesthetic appreciation, there are cognition of the object’s beautiful qualities and an appropriate emotion, but neither of these elements has great value in itself compared with that of the whole, and to have a positive emotion toward a really ugly object constitutes a whole that is evil. Beauty is thus not a matter of feeling: “The beautiful should be defined as that of which the admiring contemplation is good in itself.” Whether an object has true beauty “depends upon the objective question whether the whole in question is or is not truly good, and does not depend upon the question whether it would or would not excite particular feelings in particular persons.” Subjectivistic definitions of beauty commit the naturalistic fallacy, but it should be noted that beauty can be defined as it is above, thus leaving only one unanalyzable value term, “good.” Consideration of the cognitive element in aesthetic appreciation shows that knowledge adds intrinsic value; aside from the value of true belief as a means or that of the actual existence of the object, it is simply and clearly better to know it truly rather than merely to imagine it. Thus appreciation of a real but inferior object is better than that of a superior but imaginary one.

The second and greater good consists of the pleasures of personal affection. All the elements of the best aesthetic enjoyments plus the great intrinsic good of the object are present here. Part of the object consists of the mental qualities of the person for whom affection is felt, though these must be appropriately expressed in the bodily features and behavior.Admirable mental qualities . . . consist very largely in an emotional contemplation of beautiful objects . . . the appreciation of them will consist essentially in the contemplation of such contemplation. It is true that the most valuable appreciation of persons appears to be that which consists in the appreciation of their appreciation of other persons . . . therefore, we may admit that the appreciation of a person’s attitude toward other persons . . . is far the most valuable good we know.

From these assertions it follows that the ideal, contrary to tradition, must include material properties, because appreciation both of beauty and of persons requires corporeal expression of the valuable qualities.

Because the emotions appropriate to both beautiful objects and to persons are so widely varied, the totality of intrinsic goods is most complex, but Moore is confident that “a reflective judgment will in the main decide correctly” both what things are positive goods and the major differences in relative values. However, this is possible only by exact distinction of the objects of value judgment, followed by direct intuition of the presence, absence, or degree of the unique property, good.

Modern-day students of ethics have benefited immeasurably from Moore’s attempt to be clear and precise in the analysis of ethical principles and from his redirection of attention to the really basic questions. Some critics cannot accept certain major conclusions concerning the indefinability of “good,” its presence to intuition, its objective status, and the consequent treatment of the “naturalistic fallacy,” but even the nature and the extent of the disagreement he has aroused testify to Moore’s stature as a philosopher of ethics.