Hans Jonas is a very interesting — I am tempted to say fascinating — as well as learned philosopher. He has written perceptively about biological problems and also about the type of philosophy in which I have most confidence. I have decided, however, not to comment in much detail upon his views. This is partly because I am not sure that he is at his best in evaluating process philosophy or in analyzing "the phenomenon of life." I like him best either as an historian of ideas or as a moralist and philosopher of religion. He seems to me to stand for much that is most valuable in our spiritual heritage and also for much that is soundest in the "modern temper." In both respects I think he is closer than he fully realizes to process philosophy.