It should be observed that the same kind of change is sometimes brought about, without volition, by a powerful emotional shock, due to extraneous causes: and hence it might be inferred that in all cases it is a powerful impression of an emotional kind that produces the effect; and that the will is only concerned in concentrating our attention on the benefits to be gained or evils to be avoided by the change of habit, and so intensifying the impression of these. But though this kind of voluntary contemplation is a useful auxiliary to good resolutions, it does not seem to be this effort of will that constitutes the resolution: we can clearly distinguish the two. Hence this third effect of volition cannot be resolved into the second, but must be stated separately.