An infectious mania, it might seem,--that strange passion for nonentity, to which the Greek was so oddly liable, to which the human mind generally might be thought to have been constitutionally predisposed; for the doctrine of "The One" had come to the surface before in old Indian dreams of self-annihilation, which had been revived, in the second century after Christ, in the ecstasies (ecstasies of the pure [41] spirit, leaving the body behind it) recommended by the Neo-Platonists; and again, in the Middle Age, as a finer shade of Christian experience, in the mystic doctrines of Eckhart and Tauler concerning that union with God which can only be attained by the literal negation of self, by a kind of moral suicide; of which something also may be found, under the cowl of the monk, in the clear, cold, inaccessible, impossible heights of the book of the Imitation. It presents itself once more, now altogether beyond Christian influence, in the hard and ambitious intellectualism of Spinoza; a doctrine of pure repellent substance--substance "in vacuo," to be lost in which, however, would be the proper consummation of the transitory individual life. Spinoza's own absolutely colourless existence was a practical comment upon it. Descartes; Malebranche, under the monk's cowl again; Leibnitz; Berkeley with his theory of the "Vision of all things in God"; do but present variations on the same theme through the seventeenth and eighteenth centuries. By one and all it is assumed, in the words of Plato, that to be colourless, formless, impalpable is the note of the superior grade of knowledge and existence, evanescing steadily, as one ascends towards that perfect (perhaps not quite attainable) condition of either, which in truth can only be attained by the suppression of all the rule and outline of one's own actual experience and thought.