In his book, Nobel laureate physicist Leon Lederman refers to these famous words of Hamlet 's: "There are more things in heaven and earth," "Than are dreamt in your philosophy." In philosophy, as represented by Kantian criticism, we have endeavored to constantly identify the possibilities and limits of human cognitive ability. Therefore, from the philosophical side, it is naturally necessary to carry out self-verification based on the results of modern physics. In this paper, I will analyze a fruitful discussion on Kantian philosophy from the dialogue version of Werner Heisenberg, one of the founders of quantum mechanics, and scrutinize its contents. In the introduction, I also discuss Jaspers and Wittgenstein on agnosticism.