I’m inclined to state that Christopher Nolan took some deal of inspiration from the Yoga Vasista – a Vedantic tome that documents what Sage Vasishta expounds to Lord Rama (an avatar of lord Vishnu) on the Absolute Reality. It is a complex tome, made enjoyable by the sheer imaginative concepts expounded (with the WOW factor!) as well as prolific use of metaphors and analogies.
But back to Inception. Here are some of the excerpts from the Vasistha that I found fascinating and bearing correspondence to the concept of the movie.
“Absence of difference between waking and dreaming: There is no difference between waking and dreaming states except stability and instability. The combined experience of these two is the same always and everywhere. That is described as waking which is endowed with stable experience. That is declared as dreaming which is of unstable experience. That which was seen for a moment in the waking state might remain a dream for a different time, Such waking attains to the nature of a dream; the dream also tends towards the waking state”
“Within every world, there are other worlds. With every world there are other worlds too of different kinds. Like the basic coverings of a plantain tree, there are multitudes of worlds existing within them also. …Even extensive worlds, unseen by one another, and mutually not experienced, are born like the dream-illusions of the soldiers in an army. Very many worlds are surely born even within a small atom, like the buds of a plantain tree, abundantly and with deep insertion. Thus, even those worlds which are extended with great scenes (such as islands, oceans and continents) are not even mere grain by comparison. Even in grasping the hundred thousandth of an atom, or a moment, thousands of worlds and aeons appear completely, as if they are real. Thus in every atom in space, countless worlds exists.”
There’s more in the Yoga Vasishta on the subconscious, and the conscious. But phew! It’s exhausting. For those interested, grab a copy! I’m currently reading this version authored by Samvid. I chanced upon this in my institute’s library when I was looking out for introductory reads into the Upanishads, and similar works. In case you know of a better interpretation, or a more lucid read, do leave a comment!