So in one department of human thought--the investigation of natural processes--majestic progress has been made since the opening of the seventeenth century, with every promise of continued and startling advance. The new methods employed by students of natural science have resulted in the accumulation of a stupendous mass of information in regard to the material structure and operation of things, and the gradual way in which the earth and all its inhabitants have come into being. The nature and workings of atoms and molecules are being cleared up, and their relation to heat, light, and electricity established. The slow processes which have brought about the mountains and valleys, the seas and plains, have been exposed. The structure of the elementary cell can be studied under powerful lenses; its divisions, conjunctions, differentiation, and multiplication into the incredibly intricate substance of plants and animals can be traced. In short, man is now in a position, for the first time in his history, to have some really clear and accurate notion of the world in which he dwells and of the living creatures which surround him and with which he must come to terms. It would seem obvious that this fresh knowledge should enable him to direct his affairs more intelligently than his ancestors were able to do in their ignorance. He should be in a position to accommodate himself more and more successfully to the exigencies of an existence which he can understand more fully than any preceding generation, and he should aspire to deal more and more sagaciously with himself and his fellow-men. 13. HOW SCIENTIFIC KNOWLEDGE HAS REVOLUTIONIZED THE CONDITIONS OF LIFE But while our information in regard to man and the world is incalculably greater than that available a hundred, even fifty years ago, we must frankly admit that the knowledge is still so novel, so imperfectly assimilated, so inadequately co-ordinated, and so feebly and ineffectively presented to the great mass of men, that its _direct_ effects upon human impulses and reasoning and outlook are as yet inconsiderable and disappointing. We _might_ think in terms of molecules and atoms, but we rarely do. Few have any more knowledge of their own bodily operations than had their grandparents. The farmer's confidence in the phases of the moon gives way but slowly before recent discoveries in regard to the bacteria of the soil. Few who use the telephone, ride on electric cars, and carry a camera have even the mildest curiosity in regard to how these things work. It is only _indirectly_, through _invention_, that scientific knowledge touches our lives on every hand, modifying our environment, altering our daily habits, dislocating the anciently established order, and imposing the burden of constant adaptation on even the most ignorant and lethargic.