abstractionist

from WordNet (r) 3.0 (2006)

abstractionist
    adj 1: not representing or imitating external reality or the
           objects of nature; "a large abstract painting" [syn:
           {abstract}, {abstractionist}, {nonfigurative},
           {nonobjective}]
    n 1: a painter of abstract pictures [syn: {abstractionist},
         {abstract artist}]

from The Collaborative International Dictionary of English v.0.48

Abstractionist \Ab*strac"tion*ist\, n.
   An idealist. --Emerson.
   [1913 Webster]