Don't know if you are familiar with Dr Who (UK sci-fi TV series), but they have a race called the Daleks who were created for ethnic cleansing ... then decided that only Dalek's ahd any worth and so set out to destroy all other life in the Universe.
Kind of an extreme response to worth=similarity, but extremes often expose issues within a premise.
Well, of course it depends what similarities we choose.
But there will normally be some. It is certainly true that I could in principle afford rights arbitrarily --- randomly granting them to John, Henry, and Peter while withholding them from James, Tony, and Bill --- but in practice people will grant rights to members of a natural class (by which I mean one defined by a simple criterion). These will necessarily have something in common, which is what makes them members of a natural class.
Then if I think that
I should have these rights (and again, though in principle I might not, in practice I will) then they must all have something in common with
me that makes them and me all members of this class.
Edited by Dr Adequate, : No reason given.
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