One of the principal, and most persistent, sources of error that tends to bedevil a considerable proportion of contemporary literary analysis is the implicit assumption that the writer's creative process is a wholly conscious and purposive type of activity. Few critics stop to inquire into the psychological basis and the mechanism of the creative process itself; hence their tendency to approach a work of art in terms of the author's intentions. The excellence of a work can then be deduced from an examination of the intentions in the mind of the writer (whether they are relevant and important) and of the degree to which these intentions have been realized. And even if the complexity of the creative process is realized by a critic, once he has started to analyze, say, the imagery of a poem or play the effect on the reader will tend to be an impression that the given author deliberately chose the metaphors or images concerned rather than following a semiconscious urge to express his intuition in these, and no other, terms.