§ 5. It is, however, of obvious practical importance to ascertain how far the power of the will (whether metaphysically free or not) actually extends: for this defines the range within which ethical judgments are in the strictest sense applicable. This inquiry is quite independent of the question of metaphysical freedom; we might state it in Determinist terms as an inquiry into the range of effects which it would be possible to cause by human volition, provided that adequate motives are not wanting. These effects seem to be mainly of three kinds: first, changes in the external world consequent upon muscular contractions; secondly, changes in the train of ideas and feelings that constitutes our conscious life; and thirdly, changes in the tendencies to act hereafter in certain ways under certain circumstances.
I. The most obvious and prominent part of the sphere of volitional causation is constituted by such events as can be produced by muscular contractions. As regards these, it is sometimes said that it is properly the muscular contraction that we will, and not the more remote effects; for these require the concurrence of other causes, and therefore we can never be absolutely certain that they will follow. But no more is it certain, strictly speaking, that the muscular contraction will follow, since our limb may be paralysed, etc. The immediate consequent of the volition is some molecular change in the motor nerves. Since, however, we are not conscious in willing of our motor nerves and their changes,--nor indeed commonly of the muscular contractions that follow them,--it seems a misuse of terms to describe either as the normal ‘object’ of the mind in willing: since it is almost always some more remote effect which we consciously will and intend. Still of almost all effects of our will on the external world some contraction of our muscles is an indispensable antecedent; and when that is over our part in the causation is completed.
II. We can control to some extent our thoughts and feelings. It would seem, indeed, that an important part of what we commonly call ‘control of feeling’ comes under the head just discussed. Our control over our muscles enables us to keep down the expression of the feeling and to resist its promptings to action: and as the giving free vent to a feeling tends, generally speaking, to sustain and prolong it, this muscular control amounts to a certain power over the emotion. But there is not the same connexion between our muscular system and our thoughts: and yet experience shows that most men (though some, no doubt, much more than others) can voluntarily determine the direction of their thoughts, and pursue at will a given line of meditation. In such cases, what is effected by the effort of will seems to be the concentration of our consciousness on a part of its content, so that this part grows more vivid and clear, while the rest tends to become obscure and ultimately to vanish. Frequently this voluntary exertion is only needed to initiate a train of ideas, which is afterwards continued without effort: as in recalling a series of past events or going through a familiar train of reasoning. By such concentration we can free ourselves of many thoughts and feelings upon which we do not wish to dwell: but our power to do this is very limited, and if the feeling be strong and its cause persistent, it requires a very unusual effort of will to banish it thus.