Helena Roerich. Of secret knowledge. Theory and practice of Agni Yoga (№ 176113)

A lot of the harm brought books about all kinds of Hatha yogic exercises. What ignorance to think that the highest and subtlest can be achieved purely mechanically! You rightly write that the people, aspiring to spiritual development (and they often understand it as the achievement of mental manifestations), completely overlooked that without an effective service for the common good the development this will be a one-sided and fragile. Only communicate with people lights our interior lights only when the contact with them can we test ourselves and to sharpen and temper the blade of our spirit. Of course, need a certain isolation and periodic removal for renewed strength, but privacy can never bring the pressure of our forces, which alone enables their refinement.