"According to academic tradition this volume would be a section of philosophy, but it is really concerned with a branch of biology. It sets forth the principles generally stated in connection with the scientific study of the mental functions of living beings, having more especially to do with normal civilized man, who interests us in practical life. Instead of a simple arrangement of facts, laws and measurements, the reader will find a general exposition of mental functioning such as may be disentangled from the results hitherto obtained, with an appeal to examples of definite accomplishment. This provisional synthesis will undoubtedly appear very unlike the familiar descriptions set forth by classical psychology, from which it is difficult to free one's self in spite of their artificial character"--Preface. (PsycINFO Database Record (c) 2011 APA, all rights reserved).