But in spite of the advantages of solitude there is a hackneyed proverb about the rose and the thorn which has here a most direct application. In the same manner that every breath of frosty air injuriously affects any one who constantly keeps to his own room, so does a man's disposition become so sensitive in solitude that he is vexed and annoyed at the most trivial incident, at a word, or even at an expression of the countenance. It is hard, however, to catch Schopenhauer napping, and for this he has a remedy which, if not within the reach of all, is none the less efficacious. His recipe is simply that every aspirant should accustom himself to carry a part of his solitude into society, and learn to be alone even in a crowd; in other words, not to tell others at once what he thinks, and not to pay much attention to what others may say; in this way he will in a measure keep himself unaffected by the stupidities which must necessarily surge about him, and harden himself to exterior influences. As has been noted, it was far from Schopenhauer's intention to recommend an idle folding of the hands. Solitude is all very well, but to be habitable it must be peopled with thoughts and deeds; the essence of life is movement, and in inaction it is a most difficult thing to be tranquil. Indeed, the most thoughtless must do something, even if that something consist but in a tattoo beaten on the window-pane. Schopenhauer's words, however, are presumably not addressed to thoughtless people. To struggle and cope is, he says, as much of a necessity to man as burrowing is to the mole. To conquer resistance constitutes the fullness of human delight, and whether the obstacles are of a material nature, as in action and exercise, or purely mental, as in study and research, it is the combat and the victory that bring happiness with them.