. . . consciousness is a quantum phenomenon because it has all the peculiar characteristics of a pure quantum state, i.e., it is a definite and a private state, and so is a pure state which is not clonable., i.e., cannot be copied and therefore cannot be known by any observer. Therefore, such a state, if knowable at all, is knowable only by the system that is in that state. This crucial insight reflects remarkably the phenomenology of our inner experience.

If the current idea that consciousness emerges from the functioning of the brain were correct -- where the brain is thought to be like a classical computer -- then a computer could be conscious. But then consciousness could be copied like we routinely copy computer programs, which is classical information. Yet we know perfectly well that our experience is in constant evolution and is private, knowable only within ourselves. Moreover, the meaning we feel always exceeds any symbolic description we may produce to describe it. Therefore, even the owner of the experience (described by quantum information) can only translate a portion of its experience into symbols (described by classical information). [Emphasis in original]

Irreducible: Consciousness, Life, Computers, and Human Nature by Federico Faggin, 2024. Preface, p. 4