Believing, as I do, in the continuity of nature, I cannot stop abruptly where our microscopes cease to be of use. Here the vision of the mind authoritatively supplements the vision of the eye. By a necessity engendered and justified by Science I cross the boundary of the experimental evidence.... If you ask me whether there exists the least evidence to prove that any form of life can be developed out of matter, without demonstrable antecedent life.... [men of science] will frankly admit their inability to point to any satisfactory experimental proof that life can be developed, save from demonstrable antecedent life.
Far, however, from being a mere figment, his[{56}] mental vision is represented as the most unalloyed product of reason. He writes:[85]
Were not man's origin implicated, we should accept without a murmur the derivation of animal and vegetable life from what we call inorganic nature. The conclusion of pure intellect points this way and no other.
The conclusion of pure intellect, however, having nothing to show for itself in the way of evidence, we are again referred to a condition of things concerning which we know, and can know, nothing.
Supposing [writes the Professor][86] a planet carved from the sun, set spinning round an axis, and revolving round the sun at a distance from him equal to that of our earth, would one of the consequences of its refrigeration be the development of organic forms? I lean to the affirmative.
It is no doubt interesting to know to what opinion the Professor inclined, but is this sort of thing Science?
In the same manner Mr. Herbert Spencer, the philosopher of evolution par excellence, thus reports:[87]
Biologists in general agree that in the present state of the world no such thing happens as the rise of a living creature out of non-living matter. They do not[{57}] deny, however, that at a remote period in the past, when the temperature of the surface of the earth was much higher than at present, and other physical conditions were unlike those we know,[88] inorganic matter, through successive complications, gave origin to organic matter.[89]
Mr. Darwin himself, who is constantly supposed to have upheld, or even to have demonstrated, the fact of spontaneous generation, is amongst the strongest witnesses against it. He was indeed disposed to believe that the living will some day be found to be producible from the lifeless, the ground of his expectation being the "Law of Continuity,"[90] or the assumption that from the beginning of nature to the end one only kind of law uniformly operates, namely the same as we now experience. But this is to assume the whole[{58}] question at issue, for unless it can be shewn that there has been spontaneous generation, we cannot be assured that there is such a Law of Continuity. And despite his expectation Darwin always denied that the origin of life has been—sometimes even that it can be—explained. Thus he wrote on various occasions:
It is mere rubbish thinking at present of the origin of life; one might as well think of the origin of matter.[91]