If each of the things of nature were so wholly simple and intelligible as to present the same ideal type of beauty to all, and leave no room for individual differences of interpretation, there would be no variety in the products of artistic genius, except indeed what would result from perfect or imperfect execution. But the things of nature are complex, and in part at least enigmatical; they present different aspects to different minds and suggest a variety of interpretations; they leave large scope to the play of the imagination both as to conception of the ideal itself and as to the arrangement and manipulation of the sensible materials in which the ideal is to find expression. By means of these two functions, _conception_ and _expression_, the genius of the artist seeks to interpret and realize for us ideal types of natural beauty. The qualities of a work of art, the conditions it must fulfil, are those already enumerated in regard to beauty generally. It must have unity, order, proportion of parts; it must be true to nature, not in the sense of a mere copy, but in the sense of drawing its inspiration from nature, and so helping us to understand and appreciate the beauties of nature; it must display a power and clearness of expression adjusted to the capacity of the normal mind. We may add—as indicating the connexion of art with morality—that the work of art must not be such as to excite disapproval or cause pain by shocking any normal faculty, or running counter to any fundamental belief, sympathy, sentiment or feeling, of the human mind. The contemplation of the really beautiful, whether in nature or in art, ought _per se_ to have an elevating, ennobling, refining influence on the mind. But the beautiful is not the good; nor does the cultivation of the fine arts necessarily enrich the mind _morally_. From the ethical point of view art is one of those indifferent things which the will can make morally good or morally evil. Since man is a moral being, no human interest can fall outside the moral sphere, or claim independence of the moral law; and art is a human interest. Neither the creator, nor the critic, nor the student of a work of art can claim that the latter, simply because it is a work of art, is neither morally good nor morally bad; or that he in his special relation to it is independent of the moral law.