Starting with this opposition to mere material utility, Ruskin is careful always to define art so as to bring out its spiritual significance. 'All great Art,' he says, 'is Praise.' To him, art and religion, or art and morality, are not so much different things as different phases of the same thing. Beauty is measured, not by economic utility, or capacity to satisfy a material want, but rather by transcendental utility, or capacity to satisfy a spiritual want. In proportion as it embodies the conceptions of a great spirit, art is great. The artist ought to be faithful to nature, but mere imitation is not enough. Greatness consists in the something which the artist does not exactly add to nature, but rather educes from nature, the something which the gifted eye only can see, but which the gifted hand can make visible to others less splendidly endowed. In his application of these principles Ruskin is sometimes capricious, sometimes, perhaps, presumptuous, and very often dogmatic. His caprice is visible in his changes of opinion. We find judgments pronounced in one edition of his works with the confidence of omniscience, and retracted in another with frank self-contempt, but with unabated confidence. The reasons for the one opinion seem, as a rule, just as convincing as the reasons for the other; and while all men may legitimately change their views, frequency of change ought to beget a certain amount of diffidence. That Ruskin's criticism is sometimes presumptuous follows from its extreme confidence. He discovers the meaning of every stone in a building, and of every line and colour in a painting, in a manner hardly granted to mere man; for, after all, the most sympathetic of critics cannot enter into another man's mind, nor can the most learned completely realise a past age. This dogmatism, though irritating, is generally harmless enough; but it is not so when it results in underrating an artist like Michael Angelo, because he will not fit into the preconceived theory, and in undue exaltation of the comparatively little, because they sometimes furnish just the illustrations needed. From the same root springs the cognate fault of the intensely subjective character of Ruskin's criticism. In a celebrated passage on the Jura in the _Seven Lamps_, after an eloquent description of the scene, the writer imagines it transported to some aboriginal forest of the New Continent. In an instant it loses all its impressiveness--to him. The reason is that the element of human association is lost; and he instantly jumps to the conclusion that this element is an essential part of the charm of nature to all. Few will dispute that such association is to many an important factor in the delight in nature. But this has not been a universal feeling. Some travellers, like Darwin on the Cordilleras or in the Brazilian forests, have felt, in the midst of untrodden solitude and unbroken desolation, a sense of the sublime nowhere else to be experienced.