Full Idea
According to Goodman's 'companionship difficulty', resemblance nominalism has a problem if, say, all and only the red things were the round things, because we cannot distinguish the two different respects in which the things resemble one another.
Gist of Idea
If all and only red things were round things, we would need to specify the 'respect' of the resemblance
Source
report of Nelson Goodman (The Structure of Appearance [1951]) by Cynthia Macdonald - Varieties of Things Ch.6
Book Reference
Macdonald,Cynthia: 'Varieties of Things' [Blackwell 2005], p.230
A Reaction
Goodman opts for extreme linguististic nominalism in response to this (Idea 7952), whereas Russell opts for a sort of Platonism (4441). The current idea gives Russell a further problem, of needing a universal of the respect of the resemblance.
Related Idea
Idea 4441 'Resemblance Nominalism' won't work, because the theory treats resemblance itself as a universal [Russell]