In the old days when the Puritans went to a sermon two hours long, they listened with rapt attention to the preacher, and in so doing their minds were occupied with an entirely other subject from that which ordinarily attracted their attention. Such a diversion, even though it may seem to be pretty hard work, represents a real mental rest because the part of the brain that is usually occupied gets its rest, the blood being diverted to other parts of the brain. This may seem a paradox to some people until they are reminded that men who have lived very long lives have usually been men who turned from one form of mental work to another for diversion and rest. Gladstone, for instance, who was Prime Minister of Great Britain when past eighty years of age, was an intensely hard intellectual worker all his life, but found recreation from his political cares in the study and {142} discussion of the problems of Greek literature. Leo XIII, who lived to be ninety-three, concerned to the very end with the administration of the Church--an immense task--found his recreation in the writing of Latin poetry, though that might seem to some people too hard work of itself to be classed as rest. For a great many of these hard-working, long-lived people, as was true of both Leo XIII and Gladstone, prayer was a recourse in time of trial that made anxiety less and took the edge off solicitude and occupied the mind with the profound thought of the Providence that overrules and somehow cares for us. I have often said before medical societies, and in articles for medical journals, because the expression represents a definite medical conclusion in my mind, that the reason why nervous and mental diseases were growing commoner in our time was that men and women had no real mental recreation. They go to trivial shows of various kinds, vaudeville, musical comedy and the movies, and they laugh a little and feel a great deal, but think almost not at all. They try to forget their ordinary occupations and worries, and indeed plays and novels are now advertised as "the kind that make you forget", but they do not succeed very well in this effort and their minds are not really diverted. For diversion the mind should become occupied rather deeply with some other subject, so that the blood which has been going to a particular part of the brain in order to call up the memory of things associated with the special interests of the individual may be diverted to another part. This will give the portion of the brain previously occupied a rest as almost nothing else will. Doing nothing with the mind is impossible, though some people apparently come very {143} near it. Doing very trivial things will not divert the current of attention so as to allow of real rest. Attention is probably a matter of increased blood circulation to a particular set of brain cells. These will go on working in spite of the wish to stop, unless the blood is actually diverted elsewhere in the cerebral tissues or