302 Wiehr have to admit that their conception of the universe and of life has after all only the value of an hypothesis, indispensable to the sciences, it is true, and daily leading to new advances, but an hypothesis nonetheless. By the side of the determined material world, they recognize something undetermined, which is able to modify the results produced by purely natural causes, that is to say, they postulate the freedom of the will, thereby keeping open to mankind the way to progress, however great the obstacles with which it may be beset. In regard to human society as a whole, it is safe to say that logical thinking is a rare vice. So most people are entirely unaware of any dilemma and optimistically proceed to extricate themselves from the mire by their own bootstraps, as it were. Their optimism, from what ever source it may issue, is a valuable asset in the struggle for higher ideals. In the main part of his monograph Koller considers the advance made during the nineteenth century, taking the reader up to the present. He has here only dealt with authors on anthropogeography and certain aspects of history. In this field the theory of environment was first applied. The influences of geographical factors are still most potent, but in our age man has developed considerable efficiency in modifying the influences of geographical environment to suit his needs; other aspects of the theory of milieu have assumed equal or even greater impor- tance in our minds. Koller is aware of the fact and has planned to continue the survey of the history of the theory of environ- ment in the field of biology, jurisprudence, economics, anthropol- ogy, sociology, literature, and even physics. Since these discussions are " shortly to follow the present one," he will have to confine himself to a mere outline, as in the present case. Considered as an outline his study is a valuable guide for investigation and a good summary of the development in anthropo-geography up to date. The most important authors and phases have been briefly characterized, and what at first glance seems like an ommission, as for instance the absence of the name of Charles Darwin, who by his theories did more than any one else to bring the concept 'environment' before the educated the world over finds its explanation in Roller's plan. One thing stands out very clearly: the history of the theory of environment runs strictly parallel to the history of the human mind. JOSEF WIEHR.
Smith College.
