Doubt is the necessary tool of knowledge.

Our search for such [moral] principles can start with . . . the unconditional imperative to acknowledge every person as a person. If we ask for the contents given by this absolute, we find, first, something negative-the command not to treat a person as a thing. This seems little, but it is much. It is the core of the principle of justice.

...history has shown that the most terrible crimes against love have been committed in the name of fanatically defended doctrines.

Why does philosophy use concepts and why does faith use symbols if both try to express the same ultimate? The answer, of course, is that the relation to the ultimate is not the same in each case. The philosophical relation is in principle a detached description of the basic structure in which the ultimate manifests itself. The relation of faith is in principle an involved expression of concern about the meaning of the ultimate for the faithful.

Sometimes I think it is my mission to bring faith to the faithless, and doubt to the faithful.

Being human means asking the questions of one's own being and living under the impact of the answers given to this question. And, conversely, being human means receiving answers to the questions of one's own being and asking questions under the impact of the answers.

There is no place to which we could flee from God, which is outside of God.