The beings in the subconscient have "no heads", that is to say, there is there no mental consciousness; men have all of them such a subconscient plane in their own being and from there rise all sorts of irrational and ignorant (headless) instincts, impulsions, memories. etc. which have an effect upon their acts and feelings without their detecting the real source. At night many incoherent dreams come from this world or plane. The dark wells of the subconscient are deep and until they are altogether cleared some gushing up of the old sources is always possible.
The inner being does not depend on the subconscient, but the outer has depended on it for thousand of lives — that is why the outer being and physical consciousness's habit of response to the subconscient can be a formidable obstacle to the progress of the sadhana and is so with most. It keeps up the repetition of the old movements, is always pulling down the consciousness and opposing the continuity of the ascent and bringing the old nature or else the tamas (non-illumination and non-activity) across the descent. It is only if you live wholly and dynamically in the inner being and feel the outer as a quite superficial thing that you can get rid of the obstruction or minimise it until the transformation of the outer being can be made complete.