Chapter I: The Subject-Matter of Ethics.

§ 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 those 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. (§ 9 ¶ 1)