Unfortunately, however, Tyndall does not come to any clearness on this point, which in one possessing such a lucidity of intellect must be occasioned by his leaving his own domain of science and venturing into this metaphysical world, with which he is not so familiar. His acquaintance with the history of these studies seems not to be extensive. For example, he attributes to Herbert Spencer, as if he were the discoverer, what both Hobbes and Descartes had already stated, that there is no necessary resemblance between our sensations and the external objects from which they are derived. In regard to a belief in God, he tells us that in his weaker moments he loses it, or that it becomes clouded and dim, but that when he is at his best he accepts it most fully. This belief, therefore, is not with Tyndall a matter of conviction, founded on reason, but a question of moods. No wonder, then, that he relegates religion to the region of sentiment, and declares that it has nothing to do with knowledge. It must not touch any question of cosmogony, or, if it does, must "submit to the control of science" in that field. But what has science to do with cosmogony? Science rests on observation of facts; but our professor tells us that he obtains his great cosmological idea of "a cosmical life" by prolonging his vision backward "across the boundary of the experimental evidence." Such science as this, which is based on no experience, and is incapable of verification, has hardly the right to warn religious belief away from any field. Tyndall seems a little astray in making creation and evolution contradictory and incompatible. Evolution, he tells us, is the manifestation of a power wholly inscrutable to the intellect of man. We know that God is,--that is, we know it in our better moods,--but _what_ God is, we cannot ever know. At all events we must not consider him as a Creator. "Two courses," says Tyndall, "and only two, are possible. Either let us open our doors freely to the conception of creative acts, or, abandoning them, let us radically change our notions of matter." His objections to the idea of a Creator appear to be (1) that it is "derived, not from the study of Nature, but from the observation of men;" and (2) that it represents the Deity "as an artificer, fashioned after a human model, and acting by broken efforts as man is seen to act."