Now, although familiarity with this fact has made us forget its wonder to the extent of virtually assuming that we know all about it, philosophical enquiry shows that, besides empirically knowing it to be a fact, we only know one other thing about it, viz.—­that our knowledge of it is derived from our own activity when we ourselves are causes.  No result of psychological analysis seems to me more certain than this[47].  If it were not for our own volitions, we should be ignorant of what we can now not doubt, on pain of suicidal scepticism, to be the most general fact of nature.  Such, at least, seems to me by far the most reasonable theory of our idea of causality, and is the one now most generally entertained by philosophers of every school.

Now, to the plain man it will always seem that if our very notion of causality is derived from our own volition—­as our very notion of energy is derived from our sense of effort in overcoming resistance by our volition—­presumably the truest notion we can form of that in which causation objectively consists is the notion derived from that known mode of existence which alone gives us the notion of causality at all.  Hence the plain man will always infer that all energy is of the nature of will-energy, and all objective causation of the nature of subjective.  Nor is this inference confined to the plain man; the deepest philosophical thinkers have arrived at substantially the same opinion, e.g.  Hegel, Schopenhauer.  So that the direct and most natural interpretation of causality in external nature which is drawn by primitive thought in savages and young children, seems destined to become also the ultimate deliverance of human thought in the highest levels of its culture[48].

But, be this as it may, we are not concerned with any such questions of abstract philosophical speculation.  As pure agnostics they lie beyond our sphere.  Therefore, I allude to them only for the sake of showing that there is nothing either in the science or philosophy of mankind inimical to the theory of natural causation being the energizing of a will objective to us.  And we can plainly see that if such be the case, and if that will be self-consistent, its operations, as revealed in natural causation, must appear to us when considered en bloc (or not piece-meal as by savages), non-volitional, or mechanical.

Of all philosophical theories of causality the most repugnant to reason must be those of Hume, Kant and Mill, which while differing from one another agree in this—­that they attribute the principle of causality to a creation of our own minds, or in other words deny that there is anything objective in the relation of cause and effect—­i.e. in the very thing which all physical science is engaged in discovering in particular cases of it.