But the most common error among the whole-hearted abstractionists nowadays [in 1946] is to mistake the medium for an end in itself, instead of a means. On the other hand, the surrealists erred in supposing that one can do without a medium, that in attacking the medium one does not destroy just one means for getting into the unknown. Color and space relations constitute such a means because from them can be made structures which exhibit the various patterns of reality.

pp. 39-40 - Beyond the Aesthetics (1946)