Book excerpt: In a book that has become a milestone of scientific writing Dr. Blum uses "time's arrow," the second law of thermodynamics, as a key concept to show how the nature and evolution of the nonliving world place limits on the nature and evolution of life. He seeks to show that, from the beginning of the universe, physical and chemical laws have inexorably channeled the course of evolution so that possibilities were already limited when life first emerged. Originally published in 1951. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.