All this exercise of fancy must strengthen the imaginative faculty also. The prolonged situations, maintained sometimes whole days, or possibly weeks, give strength to the imagination and train the attention. I think, also, that the sense of essential reality, and its distinction from the unreal, the merely imagined, is helped by this sort of symbolic representation. Play has its dangers also--very serious ones. The adults sometimes set bad examples. The game gives practise in cunning no less than in forbearance. Possibly the best service of observation just now is to gather the facts with a view to the proper recognition and avoidance of the dangers. Finally, I may be allowed a word to interested parents. You can be of no use whatever to psychologists--to say nothing of the actual damage you may be to the children--unless you _know your babies through and through_. Especially the fathers! They are willing to study everything else. They know every corner of the house familiarly, and what is done in it, except the nursery. A man labours for his children ten hours a day, gets his life insured for their support after his death, and yet he lets their mental growth, the formation of their characters, the evolution of their personality, go on by absorption--if no worse--from common, vulgar, imported and changing, often immoral attendants! Plato said the state should train the children; and added that the wisest man should rule the state. This is to say that the wisest man should tend his children! Hugo gives us, in Jean Valjean and Cosette, a picture of the true paternal relationship. We hear a certain group of studies called the _humanities_, and it is right. But the best school in the humanities for every man is in his own house. With this goes, finally, the highest lesson of sport, drama, make-believe, even when we trace it up into the art-impulse--the lesson of _personal freedom_. The child himself sets the limitations of the game, makes the rules, and subjects himself to them, and then in time pierces the bubble for himself, saying, "I will play no more." All this is the germ of self-regulation, of the control of the impulses, of the voluntary adoption of the ideal, which becomes in later life--if so be that he cling to it--the pearl of great price. CHAPTER V. THE CONNECTION OF BODY WITH MIND--PHYSIOLOGICAL PSYCHOLOGY--MENTAL DISEASES.