From “Circles and Squares”:
The role of the critic is to help people see what is in the work, what is in it that shouldn’t be, what is not in it that could be. He is a good critic if he helps people understand more about the work than they could see for themselves; he is a great critic, if by his understanding and feeling for the work, by his passion, he can excite people so that they want to experience more of the art that is there, waiting to be seized. He is not necessarily a bad critic if he makes errors in judgment. (Infallible taste is inconceivable; what could it be measured against?) He is a bad critic if he does not awaken the curiosity, enlarge the interests and understanding of his audience. The art of the critic is to transmit his knowledge of and enthusiasm for art to others.
Quoted from a famous essay tackling Andrew Sarris’s “auteur” theory of cinema, excerpts from which are posted at the Keeping My Brain Alive blog.
Mencken wrote in his “Criticism of Criticism of Criticism” that the business of the critic is “to provoke the reaction between the work of art and the spectator. The spectator, untutored, stands unmoved; he sees the work of art, but it fails to make any intelligible impression on him; if he were spontaneously sensitive to it, there would be no need for criticism. But now comes the critic with his catalysis. He makes the work of art live for the spectator; he makes the spectator live for the work of art. Out of the process comes understanding, appreciation, intelligent enjoyment–and that is precisely what the artist tried to produce.”