It cannot be just a product of the body, else it could not have effect on the body and our tongues could not be moving speaking about it.
On the other side, you have people who insist that there are things which do not yield to science. So whether they admit it or not, they insist upon the existence of magic.
In fact, the definition of magic might as well be, that which does not yield to explanation. The only question once you believe in magic is, what alternative epistemology do you accept? Scripture? Tradition? Divine revelation?
This is a really valuable framing for this sort of conversation.