mental fact of changes in the quantity or quality of the light perceived? Evidently no such point of transition can be found. And not only can it not be found, but the bare hypothesis of its existence is negatived by the fact that every physical movement produces an exactly equivalent amount of physical movement; so that there is nothing whatever in the resultant which is not accounted for in the antecedents, and nothing in the antecedents which has not its full effect in the resultant. There is thus no room left for the passage of the objective fact of molecular motion into the subjective fact of feeling.
Although these considerations practically exhaust the question, yet another aspect of it may, for the sake of greater clearness, be briefly touched upon. If the doctrine of abiogenesis be accepted, it may be thought to afford some confirmation to the materialistic hypothesis that mind is but a function or property of matter. Do we not here see (it may be asked) life and sensation arising out of non-sentient materials? And if a single living creature can thus arise, then, by the doctrine of evolution, all mind whatever is affiliated on matter. Such a conclusion, however, would be quite unwarranted by the facts observed. In abiogenesis unorganic matter is seen to pass into organic matter, and this is the whole of the process known to science. To assume that at some period in this process the material constituents of the newly-formed creature acquire the property of sensation is, to say the least, a very unscientific proceeding. For, throughout all their permutations, the component elements can (or could with improved instruments) be exactly observed, measured, and weighed; enabling us to say that so and so much, such and such of the inorganic elements has become so and so much, such and such of the organic compound. Now the factors of this compound do not (ex hypothesi) contain sensation. How, then, did the compound acquire it? Where is your warrant for suddenly introducing a consequent sensation—for which you have no assignable antecedent?
Thus it is evident that between mind and matter, between spirit and body, between internal and external phenomena, there is a great gulf fixed, which no scientific or metaphysical cunning can succeed in bridging over. Matter is never sensation, and cannot be conceived as ever becoming sensation. The
