We have recently learned from our foremost investigators that a change of decisive significance is taking place in their conception of the groundwork of the mathematical sciences.1 The new position takes as its point of departure the province of physics, the findings of which have shaken the belief in the validity of the causality principle (better known to you as scientific determinism) and have inaugurated scientific methods that transcend the limitations of this basic law. I rather suppose that a turn of events of this kind surprises all of us—perhaps even imbues us, who are such strangers in the realm of physical research, with a decided uneasiness. Hitherto we understood the principle of determinism to be one of the pillars upon which the entire body of natural science was erected. The undreamed of results that consistent adherence