He wanted to find the absolute ultimate reason about himself and the world. First, he set out the rules of determination: What is not clearly realized is not true. And he doubted all that was suspicious. Better Together Luke Combs Poster. We cannot believe our eyes and other senses. Even thinking, we should not believe in it, as long as it has not been verified. It is also possible that the devil is influencing us and leading us to false conclusions! But wait – so that doesn’t mean there’s anything we can be sure of? Because, even if I doubt everything, I cannot doubt that I am skeptical, that I am a skeptic.