Every art is material—and can be only material. The possibility of using concepts, projects, ideas and political messages in art was opened by the philosophers of the “linguistic turn” precisely because they asserted the material character of thinking itself. Thinking was understood by these philosophers as the operation and manipulation of language. And language was understood by them as thoroughly material—a combination of sounds and visual signs. Now the real, epoch-making achievement of conceptual art becomes clear: it demonstrated the equivalence, or at least a parallelism, between language and image, between the order of words and the order of things, the grammar of language and the grammar of visual space.
–Boris Groys, “Introduction–Global Conceptualism Revisited,” e-flux journal #29: special issue on Moscow Conceptualism.