The difference among members of a phoneme, which we wish to find in other phonemic groupings too, is in general a relative difference in the represented speech feature. Thus when [tʰ] and [t] are put into one phoneme /t/, there is not an absolute degree of aspiration which marks the post-# member of /t/; but the post-# member will be relatively more aspirated than the post-/s/ member.
- Harris (1951), a pag.68