The explanation of the origin of life proposed by Sir W. Thomson had also occurred independently to Professor Helmholtz. This latter physicist, in an article on the use and abuse of the deductive method in Physical Science,[63] tells us very clearly what led himself, and no doubt Sir W. Thomson likewise, to suggest the meteoric hypothesis as a possible way of accounting for the origin of terrestrial life:—‘If failure attends all our efforts to obtain a generation of organisms from lifeless matter, it seems to me (says Professor Helmholtz) a thoroughly correct procedure to inquire whether there has ever been an origination of life, or whether it is not as old as matter, and whether its germs, borne from one world to another, have not been developed wherever they have found a favourable soil.’ 239. We have already sufficiently pointed out that the man of science objects to separate creations, and that, in consequence, he tries to explain the present terrestrial life by means of a single primordial germ. But the difficulty still remains regarding the original appearance of this germ. Now, according to the meteoric hypothesis, this germ may have been wafted to us from some other world, or its fragments, and thus one act of creation of life might possibly serve for many worlds. If therefore this hypothesis were otherwise tenable it would diminish the difficulty implied by separate creations, but would it entirely remove it? We doubt this very much. For, in the first place, as far as we can judge (Art. 163) the visible universe—the universe of worlds—is not eternal, while however the invisible universe, or that which we may for illustration at least associate with the ethereal medium, is necessarily eternal. The visible universe must have had its origin in time (Art. 116), no doubt from a nebulous condition. But in this condition it can hardly have been fit for the reception of life. Life must therefore have been created afterwards. We have thus at least two separate creations, both taking place in time—the one of matter and the other of life. And even if it were possible, which it is not, to get over one of the difficulties attending this hypothesis, that of creation in time, by regarding the visible universe as eternal; yet even then we must regard matter and life as implying two separate creative acts if we assume the nebulous hypothesis to be true. For if _x_ denote the date of the advent of life, and _x_ + _a_ that of the advent of matter, _a_ being a constant quantity, the two operations cannot be made simultaneous by merely increasing the value of _x_ without limit. Now this is what we mean by eternity, and therefore we cannot help thinking that this want of simultaneity implies a defect in this mode of viewing the origin of things.