It is commonly assumed that moral deliberation requires that the alternatives available in a choice situation are evaluatively comparable. This comparability assumption is threatened by claims of incomparability, which is often established by means of the small improvement argument (SIA). In this paper I argue that SIA does not establish incomparability in a stricter sense. The reason is that it fails to distinguish incomparability from a kind of evaluative indeterminacy which may arise due to the vagueness of the evaluative comparatives ‘better than,’ ‘worse than,’ and ‘equally as good as.’