Mysticism, as we have said, is the surrender of a category of thought because we divine its relativity. As every new category, however, must share this reproach, the mystic is obliged in the end to give them all up, the poetic and moral categories no less than the physical, so that the end of his purification is the atrophy of his whole nature, the emptying of his whole heart and mind to make room, as he thinks, for God. By attacking the authority of the understanding as the organon of knowledge, by substituting itself for it as the herald of a deeper truth, the imagination thus prepares its own destruction. For if the understanding is rejected because it cannot grasp the absolute, the imagination and all its works--art, dogma, worship--must presently be rejected for the same reason. Common sense and poetry must both go by the board, and conscience must follow after: for all these are human and relative. Mysticism will be satisfied only with the absolute, and as the absolute, by its very definition, is not representable by any specific faculty, it must be approached through the abandonment of all. The lights of life must be extinguished that the light of the absolute may shine, and the possession of everything in general must be secured by the surrender of everything in particular. The same diffidence, however, the same constant renewal of sincerity which kept Emerson's flights of imagination near to experience, kept his mysticism also within bounds. A certain mystical tendency is pervasive with him, but there are only one or two subjects on which he dwells with enough constancy and energy of attention to make his mystical treatment of them pronounced. One of these is the question of the unity of all minds in the single soul of the universe, which is the same in all creatures; another is the question of evil and of its evaporation in the universal harmony of things. Both these ideas suggest themselves at certain turns in every man's experience, and might receive a rational formulation. But they are intricate subjects, obscured by many emotional prejudices, so that the labour, impartiality, and precision which would be needed to elucidate them are to be looked for in scholastic rather than in inspired thinkers, and in Emerson least of all. Before these problems he is alternately ingenuous and rhapsodical, and in both moods equally helpless. Individuals no doubt exist, he says to himself. But, ah! Napoleon is in every schoolboy. In every squatter in the western prairies we shall find an owner-- "Of Caesar's hand and Plato's brain, Of Lord Christ's heart, and Shakespeare's strain."