> then once you get right down to first principles they admit that actually they think it's impossible to know the truth I've heard somewhere that one can boot

> then once you get right down to first principles they admit that actually they think it's impossible to know the truth I've heard somewhere that one can bootstrap from this point by making contingent statements since logical consequence is something that can be known with reasonable certainty. I freely admit that I'm getting out of my depth here. I just mean that if you can find a point of agreement with your interlocutor you may be able to build from there by referring to that with your next statement and so on. Its also the case that science has done a great job of finding a way (Popperian falsifiability) to get asymptotically close to truth in my opinion.