Well to my mind atheism (there are actually several incompatible definitions) seems to presume that there’s nothing we observe that can’t (at least in principle) be explained by naturalism, that science alone can (in principle) explain everything a person can observe.
This seems to be an assumption, implicit in being an atheist. If I were to show you some tangible thing, even if you do not have or know of an explanation today, you’d be 100% confident that one does exist even if we don’t yet have it.
Is this a reasonable view for me to take of it?