"The word "proof" is often understood in the strong sense of "rigorous demonstration that leaves no room for interpretation." Admitting the conclusion of a mathematical theorem does not commit freedom. It can be used in a weaker sense, but I prefer to speak of "signs", as in the Gospel according to John. They are, if you like, "clues". That an unexpected event spurs me to give thanks to God poses no difficulty to me, even if other people can see the result of chance in it. The sign presupposes the commitment of a freedom."