If a man insisted always on being serious, and never allowed himself a bit of fun and relaxation, he would go mad or become unstable without knowing it.
I want to say, in all seriousness, that a great deal of harm is being done in the modern world by belief in the virtuousness of work, and that the road to happiness and prosperity lies in an organized diminution of work.
These sudden inspirations never happen except after some days of voluntary effort which has appeared absolutely fruitless. The role of this unconscious work in mathematical invention appears to me incontestable. Rest gives back to the mind its force and freshness.
I pity the poor fellow who is so soft and flabby that he must always have "an atmosphere of good feeling" around him before he can do his work. There are such men. And in the end, unless they obtain enough mental and moral hardiness to lift them out of their soft reliance on "feeling," they are failures. Not only are they business failures; they are character failures also; it is as if their bones never attained a sufficient degree of hardness to enable them to stand on their own feet. There is altogether too much reliance on good feeling in our business organizations. People have too great a fondness for working with the people they like. In the end it spoils a good many valuable qualities.
So it comes about that if anyone spends almost the whole day in reading, and by way of relaxation devotes the intervals to some thoughtless pastime, he gradually loses the capacity for thinking; just as the man who always rides, at last forgets how to walk.
The greatest hazard of all, losing one's self, can occur very quietly in the world, as if it were nothing at all. No other loss can occur so quietly; any other loss — an arm, a leg, five dollars, a wife, etc. — is sure to be noticed.
What I urge is that you so learn to control the machinery as to live with 'day-tight compartments' as the most certain way to ensure safety on the voyage. Touch a button and hear, at every level of your life, the iron doors shutting out the dead yesterdays and the unborn to-morrows.
The mind must be given relaxation — it will rise improved and sharper after a good rest. Just as we must not force fertile farmland, for uninterrupted productivity will soon exhaust it, so constant effort will sap our mental vigor.
The only thing that consoles us for our miseries is diversion. And yet it is the greatest of our miseries. For it is that above all which prevents us thinking about ourselves and leads us imperceptibly to destruction.
