There arises a difficult question in this ideal of work. Intense activity is necessary; we must always work. We cannot live a minute without work. What then becomes of rest? Here is one side of the life-struggle — work, in which we are whirled rapidly round. And here is the other — that of calm, retiring renunciation: everything is peaceful around, there is very little of noise and show, only nature with her animals and flowers and mountains. Neither of them is a perfect picture. A man used to solitude, if brought in contact with the surging whirlpool of the world, will be crushed by it; just as the fish that lives in the deep sea water, as soon as it is brought to the surface, breaks into pieces, deprived of the weight of water on it that had kept it together. Can a man who has been used to the turmoil and the rush of life live at ease if he comes to a quiet place? He suffers and perchance may lose his mind. The ideal man is he who, in the midst of the greatest silence and solitude, finds the intensest activity, and in the midst of the intensest activity finds the silence and solitude of the desert. He has learnt the secret of restraint, he has controlled himself. He goes through the streets of a big city with all its traffic, and his mind is as calm as if he were in a cave, where not a sound could reach him; and he is intensely working all the time. That is the ideal of Karma-Yoga, and if you have attained to that you have really learnt the secret of work.
Swami Vivekananda – Complete Works Vol. 1