Understanding, therefore, does not depend upon the head, it depends upon the heart. By the help of the head one can make things more clear, they become intelligible, one can express them better, but understanding must begin to come from the heart, not from the head. Besides, with his head a person says, "Yes, it must be so because I think so, but with his heart he says, "it is so because I believe it to be so." That is the difference: in one person there is doubt, in the other conviction.