One has to go inside into the inner being and one can minimise contacts, if necessary, not as an absolute rule—provided there is a real living in the inner being and sufficient contact with outside things not to lose one’s hold of practical realities. But if there is an isolation which brings depression, inertia, unhappiness, gloom or else morbidity of any kind, then it is evident that the retirement is not wholesome.
Ref: Letters on Yoga IV