(Here a questioner asks are there not many jivas? Sri Ramana informs the questioner there is only one jiva)
A question was asked why it was wrong to say that there is a multiplicity of jivas. Jivas are certainly many. For a jiva is only the ego and forms the reflected light of the Self. Multiplicity of selves may be wrong but not of jivas.
Sri Ramana Maharshi: Jiva is called so because he sees the world. A dreamer sees many jivas in a dream but all of them are not real. The dreamer alone exists and he sees all. So it is with the individual and the world.
There is the creed of only one Self which is also called the creed of only one jiva*. It says that the jiva is only one who sees the whole world and the jivas therein.
*Tom: This is called the doctrine of eka jiva vada (the view there is only a single jiva/ego/person). Our own body-mind, and the body-mind of apparent others are all projections of the Self. Like a dream, it appears we are many, but actually this entire dream world is an illusion, and there is only the Dreamer, the Self, the Consciousness from which all is projected. Tat Tvam Asi, You are That.
The above is an excerpt taken from this longer post that further explores this theme:
Ramana Maharshi: The world should be considered like a dream