How dejection and accidie generally arise without any external provocation, as in the case of other faults.
Dejection and accidie generally arise without any external provocation, like those others of which we have been speaking: for we are well aware that they often harass solitaries, and those who have settled themselves in the desert without any intercourse with other men, and this in the most distressing way. And the truth of this any one who has lived in the desert and made trial of the conflicts of the inner man, can easily prove by experience.
Source: Conferences (New Advent)