On that basis it is impossible to literally know anything. At a certain point to function as a human some basic reasoning and common sense needs to be applied.
Yes, that's the pragmatic approach, which is necessary. But just because you apply some "basic reasoning and common sense" doesn't mean you have any more access to the truth than anyone else. Science teaches us just how much we don't know, and in fact can never know. It's worth remembering that and having some humility in our pronouncements since the very nature of our relationship to the universe leaves us largely unable to say things with certainty. As the star wars nerds say.. only the Sith deal in absolutes.