[...]... we see evidence of nature's change; every rain that falls washes the earth from the hills and mountains into the valleys and into the streams to be transported somewhere else; every wind that blows produces its small or greater effect upon the face of the earth; the beating of the ocean's waves upon the shore, the sweep of the great tides,— these, too, have their transforming power The geologists tell... Freed from the strife of primeval and medieval life, more and more observers and thinkers have enlarged the boundaries and developed the territory of the known The history of human thought itself demonstrates an evolution which began with the savages' vague interpretation of the "what" and the "why" of the universe, and culminates in the science of to-day What, now, is a science? To many people the word... the science of life has undergone far-reaching changes in coming down to its present form All the principles of these sciences are complete only in so far as they sum up in the best way the whole range of facts that they describe They cannot be final until all that can be known is known,—until the end of all knowledge and of time It is because he feels so sure of what has been gained that the man of. .. simplicity must lead the investigator to employ and apply those laws in the study of the highest natural phenomena that can be found Another motive was equally strong Too frequently men of science are accused of restricting the application of their results to their own particular fields of inquiry As individuals they use their knowledge for the development of world conceptions, which they are usually reluctant... and mode of presenting the evolutionary history of nature may be considered as the author's personal contribution to the subject Nothing has been stated that has not the sanction of high authority as well as of the writer's own conviction; but it will be clear that the believers in the truth of the analysis as made in the later chapters may become progressively fewer, as the various aspects of human... the theological beliefs of mankind Truly all the facts of knowledge are the materials of science, but science is not metaphysics or philosophy or belief, even though the student who employs scientific method is inevitably brought to consider problems belonging to these diverse fields of thought A study of nervous mechanism and organic structure leads to the philosophical problem of the freedom of the. .. definite and assignable values through an understanding of the results of science, then life may be fuller and richer, better and more effective, in direct proportion to this understanding of the harmony of the universe And so we must approach the study of the several divisions of our subject in this frame of mind We must meet many difficulties, of which the chief one is perhaps our own human nature For... PROCESS 106 V THE PHYSICAL EVOLUTION OF THE HUMAN SPECIES AND OF HUMAN RACES 150 VI THE MENTAL EVOLUTION OF MAN 197 VII SOCIAL EVOLUTION AS A BIOLOGICAL PROCESS 241 VIII EVOLUTION AND THE HIGHER HUMAN LIFE 278 INDEX 313 I EVOLUTION THE LIVING ORGANISM AND ITS NATURAL HISTORY The Doctrine of Evolution is a body of principles and facts concerning the present condition and past history of the living and... not so sure, the merely possible, and the false Having accurate and verified data, scientific method then proceeds to classify them, and this is the organizing of knowledge The final process involves a summary of the facts and their relations by some simple expression or formula A good illustration of a scientific principle is the natural law of gravitation It states simply that two bodies of matter... make up the universe It teaches that natural processes have gone on in the earlier ages of the world as they do to-day, and that natural forces have ordered the production of all things about which we know It is difficult to find the right words with which to begin the discussion of so vast a subject As a general statement the doctrine is perhaps the simplest formula of natural science, although the facts . changed, but there has been no substantial alteration of the subjects actually discussed. The choice of materials and the mode of their presentations were determined by the general purpose of the whole.