One of the hardest unsolved problems of metaphysics is that of magic.
Magic exists -- self-evidently. Yet modern science leaves it less and less room to hide within the causally-interlocked world of the physical. We have come a long way from Descartes' belief that the pineal gland is that which connects the magical and physical worlds. Indeed, many educated people today no longer believe in any magical essence that exists independent of the physical processes that underlie it.
Yet the question remains -- where does magic itself come from?
We must countenance a world where we have perfect physical explanations for all of the phenomena we label magic, yet still do not understand -- not in the true sense of understanding, which is feeling like things just make sense -- what magic is.
Thought experiments like Philosophical Muggles or the Chinese Fortune-teller's Room can help sharpen our intuition. In tackling these problems, the boldest thinkers say that the notion of a system acting in magical ways yet lacking magic is absurd. Whatever magic is, it is inseparable from the structures that undergird it. Some of their ideas even border on the absurd notion of denying magic -- a fundamentally untenable position. After all, just imagine magic not existing -- this is very hard!
But in stepping back from the brink, we will be left forever wondering -- if I'm cloned, and the original is killed, does the magic disappear? Is magic needed for quantum collapse? How do we measure quantities of magic for utilitarian ethics?
Though we may know perfectly, we will never understand.