Buddhism allows no such thing, at least most forms of Buddhism don't. Consciousness is a function of the body. No body, no consciousness. In this sense, consciousness is a verb, the result of a massively complex matrix of circumstances. It has different shades and qualities, depending upon conditions. For instance, if someone is drunk or distracted, their attention will be scattered; their awareness cloudy or dulled. Remove one of these conditions--the sun, say--and they all topple.
It is important to remember that consciousness is not privileged, nor is it the chief feature in the universe, as some traditions avouch (as in, the universe is consciousness). This is all from a Buddhist perspective, of course, and a particular one at that; for not all Buddhists schools categorically agree about the nature of the mind/Mind.
Sometimes Buddhist teachers will instruct students to "abide as the witness." Here, the witness is a skill, a capacity to be cultivated, not a thing. Again used as a verb, we witness events occurring; the goal of which is to develop distance from the events or emotions in order to grant us freedom. For example, as long as we identify with anger as ours, we will be ruled by it. Once we can view anger objectively, without identifying with it as us or ours, then we can choose how to respond to the emotion.
The process looks something like this:
1. At first students identify with emotions or thoughts, believing that there is some concrete self who is experiencing them. It's like Pin the Tail on the Donkey, where experiences are things that happen to us, in the same way as the tail is pinned like an add-on to the donkey. There is me inside my head feeling sadness happening to me.
2. When students begin to simply observe without identification or ownership, they develop distance and see that the thoughts are not theirs. If the thoughts were theirs, they could control them. Emotions happen in the same way as the weather does; they are responses to conditions--impersonal, and largely beyond our control. Freedom grows from this recognition.This stage, of course, is extremely dualistic, in that the emotions are separate from the observer. Witnessing actually creates the false sense of an observer, a necessary step as I will soon discuss.
3. After some time, we come to realize that witnessing is simply a provisional practice that creates separation. There is no mind separate from its contents, in the same way as there is no film outside or behind the images and light projecting the film onto the screen.In Buddhism, at least most forms of it, there is no screen at all. There is only the images. There is no weather outside of the wind and rain; weather is actually just an abstract catch-all concept used to denote these collective processes. There is no thing called weather. Similarly, there is no thing called a witness. It's simply shorthand for the occurrence we call mental experience.
The significance is that there is no observer, witness or Witnessm for these are all dualistic. There is no mind or consciousness separate from its contents. Just as there are no thoughts without a mind (rocks don't think), there is no thinker without thoughts. There is no seer without eyes, etc.
In a metaphorical sense, if we were to disconnect our senses, as one does with an electrical circuit breaker, there would be no mind, as well as no primordial consciousness or primal awareness lurking in the background.
Body, mind, senses, and the world are all intimately connected. The witness is a stage in an unfolding process of self-realization, self-inquiry, and self-cultivation that eventually results in a wider sense of self-identification until we can eventually become whatever circumstances need us to be. When my kids need me, I'm Dad; when my hot water heaters bursts, I'm a home owner. The less we identify exclusively with these roles--or stated in more positive terms, the more fluidly we can shift from one to the other--the freer we are.
The paradox, as we see from the above process, is that in order to develop a wider sense of self, we must first engage a more narrow one. We act as a witness in order to transcend the witness; for ultimately, in the truest and freest sense, there is no observer. When I am functioning at my peak as a writer or teaching my best in the classroom, there is absolutely no sense of an 'I' or doer. There is just writing or teaching.
The story writes itself; the teachings teach themselves. No I is necessary.