Sri Aurobindo next distinguishes between what he characterises as the “submental” consciousness inherent to the vital and physical elements of the being, and the true subconscious: “But if we draw back, if we separate the mind as witness from these parts of us, we can discover that life and body,–even the most physical parts of life,–have a consciousness of their own, a consciousness proper to an obscurer vital and to a bodily being, even such an elemental awareness as primitive animal forms may have, but in us partly taken up by the mind and to that textent mentalised. Yet it has not, in its independent motion, the mental awareness which we enjoy; if there is mind in it, it is mind involved and implicit in the body and in the physcial life: there is no organised self-consciousness, but only a sense of action and reaction, movement, impulse and desire, need, necessary activities imposed by Nature, hunger, instinct, pain, insensibility and pleasure.” This is the “submental” consciousness. It is not truly subconscious because it has its own automatic responsiveness and organisation.
Sri Aurobindo contrasts the subconscious thus: “The true subconscious is other than this vital or physical substratum; it is the Inconscient vibrating on the borders of consciousness, sending up its motions to be changed into conscious stuff, swallowing into its depths impressions of past experience as seeds of unconscious habit and returning them constantly but often chaotically to the surface consciousness, missioning upwards much futile or perilous stuff of which the origin is obscure to us, in dream, in mechanical repetitions of all kinds, in untraceable impulsions and motives, in mental, vital, physical perturbations and upheavals, in dumb automatic necessities of our obscurest parts of nature.” In fact, this subconscious is the great field of endeavor that has kept Western psychology busy for most of the last couple of centuries…..
Sri Aurobindo, The Life Divine, Book 2, Part I, Chapter 11, The Boundaries of the Ignorance