Quietism, the smug doctrine that it is enough for the mystic to give himself up to passivity and ecstasy, refraining from personal activity or social service, from intellectual improvement and aesthetic culture, was medieval Europe's counterpart of India's yoga. Philosophy walks all the way with quietists and yogis when they would have us go into retreat from the world and when they would have us learn the art of meditation. But it turns off their road when they would make retreat the business of an entire lifetime, when they proclaim a specific virtue in physical or intellectual lethargy, and when they debar positive effort in meditation in favour of a limp waiting on God. Their enjoyment of this inward rest is legitimate, but their enjoyment of it to excess--to the point where every other duty is dropped for its sake--is not. The intellect degenerates, the morals stultify, the heart shrivels. Idleness, whether of the body or the mind, is not holiness.
-- Notebooks Category 16: The Sensitives > Chapter 2: Phases of Mystical Development > # 128