The Inner Being or Inner Consciousness lies behind the Outer Consciousness, but is "external" relative to the Psychic Being which supports it. Here we have a distinct sequence of emanated hypostases, each more inner being corresponding to the "soul" relative to the outer being.
The Inner Being would seem to correspond in part to the Middle Unconscious of Psychosynthesis (no.2 in the the Egg Diagram, see comparison with Integral Psychology). It is not the same as the Collective Unconscious of Jung, because whilst a lot of the things Jung describes might be said to pertain to the Inner Being, the Collective Unconscious by its very nature is transpersonal, whereas the Aurobindoan Inner Being is a wider and vaster part of the individual, mostly latent or hidden or inactive. One contacts and actualises it through the spiritual, psychic, and occult transformation and awakening. The Inner Being has no correlation in the psychology of Freud, Adler, Behaviorism, and so on.
Sri Aurobindo makes frequent references to this aspect of our nature, as it is an important aspect of the Integral Yoga. The following entries are from some of his letters answering questions from disciples, although I have added headings in the interets of clarity, and, where relevant, some occaisonal notes. The following material appears in Letters on Yoga vol. I pp.307-312). page numbers [thus]
[p.307] There are always two different consciousnesses in the human being, one outward in which he ordinarily lives, the other inward and concealed of which he knows nothing. When one does sadhana, the inner consciousness begins to open and one is able to go inside and have all kinds of experiences there. As the sadhana progresses, one begins to live more and more in this inner being and the outer becomes more and more superficial. At first the inner consciousness seems to be the dream and the outer the waking reality. Afterwards the inner consciousness becomes the reality and the outer is felt by many as a dream or delusion, or else as something superficial and external. The inner consciousness begins to be a place of deep peace, light, happiness, love, closeness to the Divine or the presence of the Divine, the Mother. One is then aware of two consciousnesses, the inner one and the outer which has to be changed into its counterpart and instrument-that also must become full of peace, light, union with the Divine. At present you are moving between the two and in this period all the feelings you have are quite natural. You must not be at all anxious about that, but wait for the full development of the inner consciousness in which you will be able to live.
[p.308] I did not mean by the inner being the psychic or inmost being. It is the psychic being that feels love, bhakti and union with the Mother. I was speaking of the inner mental, inner vital, inner physical; in order to reach the hidden seat of the psychic one has first to pass through these things. When one leaves the outer consciousness and goes inside, it is here that one enters - some or most entering into the inner vital first, others into the inner mental or inner physical; the emotional vital is the most direct road, for the seat of the psychic is just behind the emotional in the heart-centre. It is absolutely necessary for our purpose that one should become conscious in these inner regions, for if they are not awake, then the psychic being has no proper and sufficient instrumentation for its activities; it has then only the outer mind, outer vital and body for its means and these are too small and narrow and obscure. You as yet have been able only to enter the outskirts of the inner vital and are still insufficiently conscious there. By becoming more conscious there and going deeper one can reach the psychic - the safe refuge, nirApada sthArta, of which you speak; then you will not be disturbed by the confused visions and experiences of the inner vital outskirts.
The inner consciousness means the inner mind, inner vital, inner physical and behind them the psychic which is their inmost being. But the inner mind is not the higher mind; it is more in touch with the universal forces and more open to the higher consciousness and capable of an immensely deeper and larger range of action than the outer or surface mind -but it is of the same essential nature. The higher consciousness is that above the ordinary mind and different from it in its workings; it ranges from higher mind through illumined mind, intuition and overmind up to the border line of the supramental. [...]
[p.311] They [the inner mind and the inner vital] exercise an influence and send out their powers or suggestions which the outer sometimes carries out as best it can, sometimes does not follow. How much they work on the outer depends on how far the individual has an inner life. E.g. the poet, musician, artist, thinker, live much from within - men of genius and those who try to live according to an ideal also. But there are plenty of people who have very little inner life and are governed entirely by the forces of Nature.
As one gathers experience from life to life, mental or vital, the inner mind and vital also develop according to the use made of our experiences and the extent to which they are utilised for the growth of the being.
[compare this with Theosophy, especially Leadbeater]
[p.312] Our inner being is in touch with universal mind, life and Matter; it is a part of all that, but by that very fact it cannot be in possessi- on of liberation and peace.
The psychic can have peace behind it - but the inner mind, vital and physical are not necessarily silent-they are full of movements. It is the higher consciousness that has a basis of peace.
[p.312] The inner parts in everybody remain vulgar or become high according as they are turned to the outward forces of the Ignorance or towards the higher forces from above and the inner impulsion of the psychic. All forces can play there. It is the outer being that is fixed in a certain character, certain tendencies, certain movements.
The inner being has its own time which is sometimes slower, sometimes faster than the physical.
Subjective experience of time is interstinga nd certainly needs exploring in more detail. Time always seems to go faster when we're having fun. Conversley, marijuana and psychedelics have an effect on time sensation, causing time to seem slower.