Again, the health of the body contributes directly to the power and strength of the mind. Work, which is irksome and comparatively badly done by a man who, for any cause, digestive or otherwise, is in only moderate health, will be done by the same man with zest and far better results if he is in good health. Also, the mind is able to accomplish not only better work but more work, when the whole system is not laid under a general tax to repair and make well any enfeebled or clogged organ. A single rusty joint, a badly fitting valve in an engine, makes the whole run less smoothly than it should, and also implies a waste of energy. Body and mind together, working in co-operation as they always must, are a close parallel to this. The one cannot possibly be at its best unless the other is in health. Rightful activity in the one stimulates activity in the other, just as artificial stimulants, such as spirits to the body, induce a mental activity in all respects like the physical one, temporary in character and followed by reaction. But the habit of briskness, of activity, of quick decision, is a thing fully as much mental as it is bodily; the two are inseparable, and, therefore, in the training of the body, the qualities which we should aim to acquire are those which are mentally desirable. One man’s mind may, it is true, be naturally a much less fine instrument on its own level than his body, and much less easily trained, but the self-control, the alertness, the habit of speed, which such training as we have sketched out gives, will directly and inevitably affect his mind. It may still be slow and laborious in its workings, but it would otherwise have been slower. Also, whatever work it does it does better, because it is not clogged, hindered, and distracted by an unhealthy body. Now this interweaving of mind and body is so complex, so closely knit, that it would perhaps be beyond the sphere of safety to say that the knitting together of the body and that within us which is the spring of moral, not intellectual qualities, the soul in fact, is closer than that of the mind and body. In any case, the interdependence of body on soul, of soul on body, and of both on the mind is practically complete, and this human trinity makes up man. There is no healthful habit of body which does not directly exercise a healthful influence on the soul, no harmful habit which does not hurt it. The body sins, and in its secret place the soul sickens. From the other side, also, a high moral standard infallibly leads the body to adopt healthy habits, a low moral standard suffers it to drift into physical crime and degradation.