proof is seldom appropriate. Recall Polanyi’s statement that scientifically he was able to commit himself to what he believed to be true, though he knew it might be false. The bottom-up thinker in science or theology lives by reasonable faith but not by certain sight. Even in mathematics a degree of commitment is called for, since Kurt Goedel has shown that axiomatised systems cannot establish their own consistency by means of internal argument. In their explorations of reality both science and theology