Moore's substitution is taken for granted. It occurs without announcing itself, in silence—an unnoticed ellipsis, even from its own author, who asserts a few lines later that nothing can take the place of 'good'. Yet this silence is far from empty. It is an eloquent silence. This ellipsis, which as such borders on a region of non-being, is charged, in all its apparent emptiness, with the full authority of the past.

What we see here is a twofold disappearance of the concept of value.

First, 'value' disappears as a concept with independent standing, since an analytic identity is assumed between 'good' and 'value'. Value is reduced to a mere synonym for 'good' and serves as an empty shell. 'Value' would at least retain the dignity of a genuine concept if a synthetic identity with 'good' were affirmed—but this is not the case.

More significantly still, 'value' disappears even as a synonym, since Moore repeatedly insists that nothing can be substituted for 'good'—in direct contradiction with the substitution he has just performed. If all that can be said is 'good is good', then we cannot even claim that 'good is value', not even as a tautology.
In other words, the concept of value still retained a certain 'dignity' as a synonym, however hollow. Now even that is stripped away. 'Value' is no longer even a synonym; it is a shadow—a word that vanishes as soon as it is uttered, the moral philosophy equivalent of the point in mathematics: something with no length, width, or depth, closer to nothingness than to being.

Moore's book is therefore fascinating in that it condenses and epitomises the phenomenon at work throughout the history of moral philosophy: the disappearance of the concept of 'value' in favour of the concept of 'good'.

2) The Confusion of Good/Value/Price/Duty/Existence

The passage we have just examined is not the only one in which this confusion arises. Moore continues—despite his stated intentions—to offer synonyms for the word 'good'. For example: 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 ¹.

No fewer than four concepts are here analytically identified with the good: price, value, duty, and existence (or, if one prefers, 'ought to exist'). 'Ought to' designates a 'duty' or 'moral obligation'.
In other words, to be good is to have a price, to have a value, or to be under an obligation to exist.
These three or four concepts, as synonyms of the good, are therefore synonymous with one another: they share the same meaning.
Yet to say that having value is to have a duty to exist involves two errors at once: the conflation of value with duty, and a dogmatic—and unexamined—assumption that only what exists can have value. Against this, one may advance the axiological position that what has value is precisely what is dreamt of, the ideal, or what we might call artificial paradises.

1. Ibid., chap.1, §13