Why not?
Because likeness is sameness of affections.
Yes.
And sameness has been shown to be of a nature distinct from oneness?
That has been shown.
But if the one had any other affection than that of being one, it would be affected in such a way as to be more than one; which is impossible.
True.
Then the one can never be so affected as to be the same either with another or with itself?
Clearly not.
Then it cannot be like another, or like itself?