§ 58. A few paragraphs only, can be devoted to a second division of our subject that here presents itself. To pursue in detail the laws of effect, as applying to the larger features of composition, would carry us beyond our limits. But we may briefly indicate a further aspect of the general principle hitherto traced out, and hint a few of its wider applications.

§ 59. Thus far, then, we have considered only those causes of force in language which depend upon economy of the mental energies: we have now to glance at those which depend upon economy of the mental sensibilities. Questionable though this division may be as a psychological one, it will yet serve roughly to indicate the remaining field of investigation. It will suggest that besides considering the extent to which any faculty or group of faculties is tasked in receiving a form of words and realizing its contained idea, we have to consider the state in which this faculty or group of faculties is left; and how the reception of subsequent sentences and images will be influenced by that state. Without going at length into so wide a topic as the exercise of faculties and its reactive effects, it will be sufficient here to call to mind that every faculty (when in a state of normal activity) is most capable at the outset; and that the change in its condition, which ends in what we term exhaustion, begins simultaneously with its exercise. This generalization, with which we are all familiar in our bodily experiences, and which our daily language recognizes as true of the mind as a whole, is equally true of each mental power, from the simplest of the senses to the most complex of the sentiments. If we hold a flower to the nose for long, we become insensible to its scent. We say of a very brilliant flash of lightning that it blinds us; which means that our eyes have for a time lost their ability to appreciate light. After eating a quantity of honey, we are apt to think our tea is without sugar. The phrase "a deafening roar," implies that men find a very loud sound temporarily incapacitates them for hearing faint ones. To a hand which has for some time carried a heavy body, small bodies afterwards lifted seem to have lost their weight. Now, the truth at once recognized in these, its extreme manifestations, may be traced throughout. It may be shown that alike in the reflective faculties, in the imagination, in the perceptions of the beautiful, the ludicrous, the sublime, in the sentiments, the instincts, in all the mental powers, however we may classify them-action exhausts; and that in proportion as the action is violent, the subsequent prostration is great.

§ 60. Equally, throughout the whole nature, may be traced the law that exercised faculties are ever tending to resume their original state. Not only after continued rest, do they regain their full power not only do brief cessations partially reinvigorate them; but even while they are in action, the resulting exhaustion is ever being neutralized. The two processes of waste and repair go on together. Hence with faculties habitually exercised—as the senses of all persons, or the muscles of any one who is strong—it happens that, during moderate activity, the repair is so nearly equal to the waste, that the diminution of power is scarcely appreciable; and it is only when the activity has been long continued, or has been very violent, that the repair becomes so far in arrear of the waste as to produce a perceptible prostration. In all cases, however, when, by the action of a faculty, waste has been incurred, some lapse of time must take place before full efficiency can be reacquired; and this time must be long in proportion as the waste has been great.