Living creatures are the subject of the mere biologist's merely scientific inquiry—not life. When a biologist, speaking as biologist, tries to tell us both _that_ life is and _what_ it is, he is philosophizing. Life is in fact an ultra-scientific problem. We have to call in philosophy before we can even state the problem. And when either the biologist or the physicist or the chemist talks of life as a mode of physical or chemical energy, or as a product of things, he is playing at philosophy, not soberly working at his science. The biologist shall teach us about living creatures, the physicist and the chemist about physical and chemical things and powers; but the philosopher must help us in our enquiry about life. And this, not because a man shall not be permitted to transgress boundaries we lay down, but because his chosen methods preclude his walking safely except within boundaries they themselves build up. Of every specialist this is true. We must transcend specialism if we would have 'all things, like the stars in heaven,' shed 'their light upon one another.' ------- CHAPTER II Time hath endless rarities, and shows of all varieties; which reveals old things in heaven, makes new discoveries in earth, and even earth itself a discovery. _Sir Thomas Browne_. The green leaf of the tree, the blade of the wheat that gives me bread—I look at them and tell myself, as many a man has told himself before, that if I could read their secrets I should know, as from the 'flower in the crannied wall,' 'what God and man is.' So I might, but only as far as their secrets go. If I could read my own I should go farther and know more. I am man and hold far greater secrets in being man. And I have the inestimable advantage of being inside myself, of being alive, besides looking on at living, of both growing and watching growth. There is no other live creature on earth who can possibly tell me as much as I can tell myself about what it means to be alive. And if the blade of wheat is wonderful beyond words, what am I?