That G. E. Moore’s Principia Ethica has attained the status of a modern classic is amply attested by the number of references made to its central concepts and arguments. Moore’s central contention is that the adjective “good” refers to a simple, unique, and unanalyzable property. He claims that propositions containing value terms and ethical predicates are meaningful and can be found to be either true or false, even though the word “good” names an indefinable property knowable only by intuition or immediate insight. Moore also argues that the truth of propositions predicating intrinsic goodness—that is, that something is good on its own account, quite without reference to its value as a means—must likewise be seen immediately and without proof. The term “naturalistic fallacy” is proposed to name the error of mistaking some property other than goodness for goodness itself. Any definition of “good” would involve reference to something having distinguishable aspects or parts—hence, not simple; but since goodness is simple, any such definition would be false, an instance of the naturalistic fallacy.

The failure of previous systems of ethics, Moore alleges, is attributable to their imprecise formulations of the questions peculiar to ethics. His objective is to discover and lay down those basic principles according to which any scientific ethical investigation must proceed. Ethics should be concerned with two basic questions: “What kinds of things ought to exist for their own sakes?”—which presupposes knowledge of good—and “What kinds of actions ought we to perform?”

Defining Good

The first task of ethics, then, is to determine what “good” means. The only relevant type of definition is not a verbal definition but one that describes the real nature of what is denoted by stating the parts constituting the whole referent. However, in this sense of “definition,” “good” cannot be defined. It is a simple notion, not complex. The word “good,” like “yellow,” refers to an object of thought that is indefinable because it is one of many similarly ultimate terms presupposed by those complex ones that can be defined. True, one can give verbal equivalents of these notions; for example, yellow can be described in terms of light vibrations of certain frequencies—as the physicist might describe it—but light waves are obviously not identical with yellow as experienced. One either knows yellow in one’s experience or does not, for there is no substitute for the visual experience. Likewise, while there are other adjectives, such as “valuable,” that can be substituted for “good,” the property itself must be recognized in an act of direct insight.

With respect to the notion of good (as a property indicated by the adjective, not as a substantive, “a good” or “the good”), and to propositions predicating intrinsic goodness, Moore is an intuitionist. Such propositions are simply self-evident; proof is neither possible nor relevant. However, in other respects Moore rejects intuitionism; he denies...

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The Naturalistic Fallacy

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.

Organic Unities

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...

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Metaphysical Ethics

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...

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Good and Aesthetics

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....

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Additional Reading

Ayer, Alfred Jules. Russell and Moore: The Analytical Heritage. Cambridge, Mass.: Harvard University Press, 1971. Discusses G. E. Moore’s early Platonism, his theory of truth, his conception of philosophical analysis and its aims, and his defense of “common sense,” all in the clearest terms. Concludes by noting that, for Moore, philosophical problems are not only genuine but also capable of being solved.

Fratantaro, Sal. The Methodology of G. E. Moore. Brookfield, Vt.: Ashgate, 1998. This book aspires to see the range of Moore’s methodology by exploring its intricacy and richness....

(The entire section is 394 words.)