Nevertheless, the later idealists, ungrateful to Locke for their first principle, were ungrateful also to Leibniz for their ultimate conception, anticipated by him in all its completeness. There were reasons, of course, for this ingratitude. Leibniz, like the transcendentalists, had supposed that the objects of sense, as experience reveals them, were begotten out of the latent nature of the soul; but he had also conceived that there were many souls, as many as atoms in the physical world, and that the images arising in each were signs of the presence and actual condition of its companions. Thus perception, while yielding directly only an idea, as in a dream, was indirectly symbolic of an outer reality, like a dream significant and capable of interpretation. And being an undaunted rationalist, Leibniz assumed that the sooth-sayer capable of reading this dream was reason, and that whatever reason conceived to be right and necessary actually must be true in the great outer world. It was at this point that Kant deviated into his radical subjectification of knowledge. His mind had been more open than that of Leibniz to the influences of English psychology, it had stewed longer in its [Pg 35] own juice, and he could not help asking how, if the senses could reveal only ideas of sense, reason was ever able to reveal anything but ideas of reason. Those inferences about the vast world outside, which Leibniz had allowed his spirits to make in their solitary confinement, were reduced by the more scrupulous Kant to scribblings upon their prison walls. These scribblings he officially termed the ideas of pure--that is, of unsupported--reason; but in his private capacity he gently continued to agree with Leibniz and to believe them true. There was no anomaly, according to Kant, in this situation. An idea might by chance be the image of a reality, but we could never know that it was. For the proof would have to be supplied by a further idea, and would terminate in that. The hypothesis and the corroboration would alike be mental, since experience was of ideas and could envisage nothing but the vicissitudes of the mind. If you had asked Leibniz what determined the order in which perceptions came into any mind, he would doubtless have answered that the Creator did so, or (translating that symbol into its analytic equivalent in his system) that what did so was the innate destiny or predisposition of that mind to develop in harmony with the best possible universe. Here is a very remarkable unconscious principle of [Pg 36] evolution seated in the spirit and presiding over all its experience. This is precisely what is meant by a transcendental principle.