nominalism n.

"the view that treats abstract concepts as names only, not realities; the doctrine that common nouns are mere conveniences in thought or speech, representing nothing in the real things," 1820, from French nominalisme (1752), from nominal, from Latin nominalis "pertaining to a name or names" (see nominal). Related: Nominalist (1650s); nominalistic.

Medieval thinkers, especially those of the twelfth century, are classified as being either nominalists or realists; modern philosophers have generally joined in the condemnation of medieval realism, but have nevertheless been mostly rather realists than nominalists. [Century Dictionary, 1895]