"In the Middle Ages.... There was available for imitation a universally valid conceptual reality, whose order the artist
could not tamper with. The subject matter of art was prescribed by those who commissioned works of art, which were not created,
as in bourgeois society, on speculation. Precisely because his content was determined in advance, the artist was free to concentrate
on his medium. He needed not to be philosopher, or visionary, but simply artificer. As long as there was general agreement
as to what were the worthiest subjects for art, the artist was relieved of the necessity to be original and inventive in his
'matter' and could devote all his energy to formal problems. For him the medium became, privately, professionally, the content
of his art, even as his medium is today the public content of the abstract painter's art - with that difference, however,
that the medieval artist had to suppress his professional preoccupation in public - had always to suppress and subordinate
the personal and professional in the finished, official work of art. If, as an ordinary member of the Christian community,
he felt some personal emotion about his subject matter, this only contributed to the enrichment of the work's public meaning.
Only with the Renaissance do the inflections of the personal become legitimate, still to be kept, however, within the limits
of the simply and universally recognizable. And only with Rembrandt do 'lonely' artists begin to appear, lonely in their art.
But even during the Renaissance, and as long as Western art was endeavoring to perfect its technique, victories in this realm
could only be signalized by success in realistic imitation, since there was no other objective criterion at hand. Thus the
masses could still find in the art of their masters objects of admiration and wonder."
- Clement Greenburg, 'Avant-Garde & Kitsch'