Several fruitless attempts have been made to reduce criticism to an exact science, which, quite disregarding the factor of personal taste, could refer all literature to a more or less fixed and arbitrary set of critical principles. The champions of this objective criticism point to the occasionally ludicrous divergence of the views expressed in criticism of certain poets or novelists, and insist that there is no occasion for such a bewildering difference of opinion. They seem to forget that the criticism which we esteem most highly at all times is the subjective criticism in which the personality of a competent and sincere critic is manifest. Literature, like music, painting and the other arts, has its own laws of technique--fundamental canons that must be observed in the successful pursuit of the art; but at a certain point difference of opinion is not only possible but profitable. The critics who would unite in condemning a thirteen-line sonnet or a ten-act tragedy could not be expected to agree on the relative merits of Milton's and Wordsworth's sonnets. Unanimity of opinion is as impossible and undesirable concerning the poetic achievement of Browning and Whitman as it is concerning the music of Brahms and Wagner, or the painting of Turner and Whistler. Great artists who have taken liberties with traditions and precedents have done much to prevent the critics from falling into a state of self-complacency over their scientific methods and formulas. The most helpful form of criticism is the interpretative variety, not necessarily the laudatory "appreciation" that is so popular in our day, but an honest effort to understand and elucidate the intention of the writer. The proper exercise of this art occasionally demands rare qualifications on the part of the critic; at the same time it adds dignity to his calling and value to his utterance. It serves to dispel the popular conception of a critic as a disappointed _litterateur_ who begrudges his more brilliant fellow craftsmen their success and who dogs their triumphs with his ill-tempered snarling. Interpretative criticism needs few rules and no system; yet it serves a noble purpose as a guide and monitor for subsequent literary effort.