The poetic and the metaphysical temperaments are generally held to be in some sense incompatible. Poets, indeed, have often shown the highest speculative acuteness, and philosophy often implies a really poetical imagination. But the necessary conditions of successful achievement in the two cases are so different that the combination of the two kinds of excellence in one man must be of excessive rarity. No man can be great as a philosopher who is incapable of brooding intensely and perseveringly over an abstract problem, absolutely unmoved by the emotion which is always seeking to bias his judgment; whilst a poet is great in virtue of the keenness of his sensibility to the emotional aspect of every decision of the intellect. For the one purpose, it is essential to keep the passions apart from the intellect: for the other, to transfuse intellect with passion. A few of our metaphysicians have ventured into poetical utterance. Berkeley wrote a really fine copy of verses, and Hobbes struck out one famous couplet— And like a star upon her bosom lay His beautiful and shining golden head— in a translation of Homer, otherwise not easily readable. Scott proposed to publish the whole poetical works of David Hume, consisting of a remarkable quatrain composed in an inn at Carlisle.[6] Here chicks in eggs for breakfast sprawl, Here godless boys God's glories squall, Here Scotchmen's heads do guard the wall, But Corby's walks atone for all. The only exception to this rule in our literature seems to be Coleridge. Coleridge undoubtedly exercised a vast influence upon the speculation of his countrymen, whilst his poems possess merits of the rarest order. It is more worthy of remark that his poetry is most successful where it is most independent of his philosophy. In 'Christabel,' the 'Ancient Mariner,' or 'Kubla Khan,' we can only discover the philosopher by the evidence of a mind richly stored with associations, and by the tendency to discover a mystical significance in natural objects. Some people would urge that his philosophy would have been improved if it had been equally free from poetical elements. In any case, Coleridge is an example of a combination of diverse excellence not easily to be paralleled. Another poet was supposed by some of his admirers to have similar claims upon our respect. Shelley seems to have thought himself as well fitted for abstract speculation as for poetry; and his widow declared that, had he lived longer, he might have 'presented to the world a complete theory of mind; a theory to which Berkeley, Coleridge, and Kant would have contributed; but more simple, unimpugnable, and entire than the systems of those writers.' The phrase is by itself enough to prove Mrs. Shelley's incompetence to form any opinion as to her husband's qualifications for this stupendous task. It is not by forming a patchwork of Berkeley, Kant, and Coleridge that a 'complete theory of mind' is