From the PREFACE . It is possible that the title of this book may be misleading to some readers, and so an explanation may, very appropriately, form the subject of this introduction. Well, then, by " the mechanism of life " is meant nothing more than the results of a scientific analysis of the activities of living animals. First, we must define what is meant by " scientific method," and this is not at all difficult now that Einstein, Eddington, and the other relativists, have persuaded us to think about what we do when we investigate something " scientifically." What we do, in that case, "is to observe space-time coincidences in a four- dimensional manifold - that is really and actually our procedure, though it seems rather dreadful! It would be very inconvenient, also, to sustain oneself in this plane all the while, and so we proceed to let ourselves down to earth, so to speak. From the space coincidences that we observe (for instance, the coincidences of the top of a column of mercury in a barometer tube with certain marks on the adjoining scale) we infer space measurements, and from the coincidences of the hands of a clock with marks on the dial we infer time measurements. That simplifies the method a good deal.