Full Idea
Goodman's 'imperfect community' problem for Resemblance Nominalism says that without mention of respects in which things resemble, we end up with a heterogeneous collection with nothing wholly in common (blue book, blue pen, red pen, red clock).
Clarification
'Heterogeneous' means all different
Gist of Idea
Without respects of resemblance, we would collect blue book, blue pen, red pen, red clock together
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.231
A Reaction
This suggests Wittgenstein's 'family' resemblance as a way out (Idea 4141), but a blue book and a red clock seem totally unrelated. Nice objection! At this point we start to think that the tropes resemble, rather than the objects.
Related Idea
Idea 4141 Various games have a 'family resemblance', as their similarities overlap and criss-cross [Wittgenstein]