Let me start with an analogy. Say we are rummaging through drawer and find an old plastic model of a spaceship, and then we ask ourselves: "Does the spaceship this is a model of actually exist?" It's a peculiar and difficult question. On one hand, the spaceship our model points to does exist conceptually, or we would not recognize it as a model of anything. Even if it's a model of the Millennium Falcon it exists in that sense, as something identifiable. On the other hand, if we find a model of (say) a Saturn 5 rocket, we want to say that the thing it points to exists (or at least existed) in a more material, physical sense, not as mere concept.
This is the position we are always in. Consciousness presents us with a kind of internal scale model of the universe, and we are always left wondering whether the universe our internal scale model points to exists. Our inner scale model is incomplete and inaccurate; parts of it are wrong; parts of it are pure fantasy... But parts of it (we like to think) reflect a true and proper understanding of something that is entirely outside of our heads: that existed before our inner world existed and will continue to exist after our inner world is gone.
We are left with an array of choices (with myriad variations of each):
- Solipsism, in which consciousness is synonymous with reality, no one has an inner life except you, and the universe begins at your first perception and ends at your last.
- Physicalism, in which reality supersedes and subsumes consciousness, so that our inner lives are mere extensions or derivations of reality.
- Transcendental thought, in which consciousness exists over and above a fundamental reality, neither encompassing it entirely nor reducing to it specifically.
There are no analytical grounds to embrace or reject any of these positions, so the choice usually comes down to aesthetics, or polemics, or mere habit.