As we have already intimated, we do not hold Mr Ruskin to be a safe guide in matters of art, and the present volume demonstrates that he is no safe guide in matters of philosophy. He is a man of undoubted power and vigour of mind; he feels strongly, and he thinks independently: but he is hasty and impetuous; can very rarely, on any subject, deliver a calm and temperate judgment; and, when he enters on the discussion of general principles, shows an utter inability to seize on, or to appreciate, the wide generalisations of philosophy. He is not, therefore, one of those men who can ever become an authority to be appealed to by the less instructed in any of the fine arts, or on any topic whatever; and this we say with the utmost confidence, because, although we may be unable in many cases to dispute his judgment--as where he speaks of paintings we have not seen, or technicalities of art we do not affect to understand--yet he so frequently stands forth on the broad arena where general and familiar principles are discussed, that it is utterly impossible _to be mistaken in the man_. On all these occasions he displays a very marked and rather peculiar combination of power and weakness--of power, the result of natural strength of mind; of weakness, the inevitable consequence of a passionate haste, and an overweening confidence. When we hear a person of this intellectual character throwing all but unmitigated abuse upon works which men have long consented to admire, and lavishing upon some other works encomiums which no conceivable perfection of human art could justify, it is utterly impossible to attach any weight to his opinion, on the ground that he has made an especial study of any one branch of art. Such a man we cannot trust out of our sight a moment; we cannot give him one inch of ground more than his reasoning covers, or our own experience would grant to him. We shall not here revive the controversy on the comparative merits of the ancient and modern landscape-painters, nor on the later productions of Mr Turner, whether they are the eccentricities of genius or its fullest development; we have said enough on these subjects before. It is Mr Ruskin's book, and not the pictures of Claude or Turner, that we have to criticise; it is his style, and his manner of thinking, that we have to pass judgment on.