point to be noted here is that some children, from whatever cause, may be in a more or less constant state of fatigue all or most of the time; and since fatigue produces what is called dullness, these unfortunates will be distinguished as dullards and stupids, unless the greatest care be taken in home and school to conserve their nervous energy. If such care is not taken, a chronic condition is established in the nervous system which permits the energy to escape in useless ways; and if this continues long enough, perhaps through the college period, it is doubtful if the individual will ever fully recover, since the nerve cells probably acquire their permanent modes of action by this time.
Thus far nothing has been said of the effects of fatigue upon emotional states. It is manifestly much more difficult, if at all possible, to obtain data respecting this question by scientific experiment; we must rely rather almost wholly upon observation. Doubtless every one has had sufficient experience to be assured that irritability is in many persons an almost certain consequence of unusually severe mental strain or worry.[1] It has already been pointed out that in a state of fatigue the nerve cells are unstable, giving off energy—exploding as it were—without sufficient cause. A person who when refreshed and vigorous would be able to inhibit impulses to anger, or quick words, or passion of any sort, would probably in a state of fatigue lose this power, at least in a measure. That is, fatigue in most instances lessens the inhibitory action of cerebral cells, and the individual reacts upon every stimulus without, as we say, deliberation or consideration. It is shown, too, by some investigators[2] that fatigue produces a melancholy, depressed feeling; causes one to turn his thoughts in upon himself, and to become morbid and gloomy if this self-consciousness is long continued. Further, it is the opinion of those who have had large experience that those qualities of character which are described by the terms vicious or criminal are due to perverted feelings dependent upon impaired physical conditions,[3] especially of the nervous system. It has become a maxim that a man in a state of hunger is much harder to govern than when he is well nourished. Untruthfulness, which Kant has called the negation of self, is generally a characteristic of an individual who has not vigor enough to face boldly the consequences of his acts. It would doubtless be within bounds to say that in general one who is physically weak, who is nervously depleted, is usually, although perhaps not always, morally weak.
