I do not think any who do not acquire--and it takes a hard effort to acquire--this notion of a transmitted nerve element will ever understand 'the connective tissue' of civilisation. We have here the continuous force which binds age to age, which enables each to begin with some improvement on the last, if the last did itself improve; which makes each civilisation not a set of detached dots, but a line of colour, surely enhancing shade by shade. There is, by this doctrine, a physical cause of improvement from generation to generation: and no imagination which has apprehended it can forget it; but unless you appreciate that cause in its subtle materialism, unless you see it, as it were, playing upon the nerves of men, and, age after age, making nicer music from finer chords, you cannot comprehend the principle of inheritance either in its mystery or its power.
These principles are quite independent of any theory as to the nature of matter, or the nature of mind. They are as true upon the theory that mind acts on matter--though separate and altogether different from it--as upon the theory of Bishop Berkeley that there is no matter, but only mind; or upon the contrary theory--that there is no mind, but only matter; or upon the yet subtler theory now often held--that both mind and matter are different modifications of some one tertium quid, some hidden thing or force. All these theories admit--indeed they are but various theories to account for--the fact that what we call matter has consequences in what we call mind, and that what we call mind produces results in what we call matter; and the doctrines I quote assume only that. Our mind in some strange way acts on our nerves, and our nerves in some equally strange way store up the consequences, and somehow the result, as a rule and commonly enough, goes down to our descendants; these primitive facts all theories admit, and all of them labour to explain.
Nor have these plain principles any relation to the old difficulties of necessity and freewill. Every Freewillist holds that the special force of free volition is applied to the pre-existing forces of our corporeal structure; he does not consider it as an agency acting in vacuo, but as an agency acting upon other agencies. Every Freewillist holds that, upon the whole, if you strengthen the motive in a given direction, mankind tend more to act in that direction. Better motives--better impulses, rather--come from a good body: worse motives or worse impulses come from a bad body. A Freewillist may admit as much as a Necessarian that such improved conditions tend to improve human action, and that deteriorated conditions tend to deprave human action. No Freewillist ever expects as much from St. Giles's as he expects from Belgravia: he admits an hereditary nervous system as a datum for the will, though he holds the will to be an extraordinary incoming 'something.' No doubt the modern doctrine of the 'Conservation of Force,' if applied to decision, is inconsistent with free will; if you hold that force 'is never lost or gained,' you cannot hold that there is a real gain--a sort of new creation of it in free volition. But I have nothing to do here with the universal 'Conservation of Force.' The conception of the nervous organs as stores of will-made power does not raise or need so vast a discussion.