Art history as art criticism?

Whenever one tries to think about the essence of art history, inevitably the ąuestion of judgement comes to the fore. But what kind of judgement is it? Is it the Vasari type of rise and decline of values, the avant-garde search for transgression or the post-modern principle of multiplicity? What is the relation between the apparent objectivity of the collection of facts and figures and its inherent structures of evaluation? And fmally to what extent is art history able to formulate judgements and to what extent they are conditioned on the one hand by art criticism and on the other by contemporary art?