In Science the paramount appeal is to the Intellect - its purpose being instruction; in Art, the paramount appeal is to the Emotions - its purpose being pleasure. A work of Art must of course indirectly appeal to the Intellect, and a work of Science will also indirectly appeal to the Feelings; nevertheless a poem on the stars and a treatise on astronomy have distinct aims and distinct methods. But having recognised the broadly-marked differences, we are called upon to ascertain the underlying resemblances. Logic and Imagination belong equally to both. It is only because men have been attracted by the differences that they have overlooked the not less important affinities.