If you make a distinction between self, or pure consciousness and mind or 'applied' consciousness, then you see that while there is no limit to the forms in which consciousness reveals itself to itself, none of these encroach upon the fundamentally unitary and unmanifested nature of pure consciousness. The analogy is made with light which only appears when it strikes something it an object or a retina, and a similar analogy could be made with electricity which brings about so many diverse actions and manifestations but is, apart from what it does, devoid of any nature. There are derived theories however, explaining the nature of light or of electricity in terms of the action of yet more fundamental elements. In the same way, pure consciousness, may be the action, the 'mind' of a somewhat yet more unitary and unrevealed.