In simplest terms that don't depend too heavily on philosophical references or terminology, I believe he means the philosophical task shouldn't be to prove a th

In simplest terms that don't depend too heavily on philosophical references or terminology, I believe he means the philosophical task shouldn't be to prove a thing is or isn't, but that a thing could be—that a set of plausible explanations exist or could exist to provide enough convincing power that a given system of thought or a different state of affairs is not impossible to conceive of or consider capable of existing.