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. 



Then it is only the relations between series of space-time 

 measurements that form the data of science (its differential 

 equations), but that, again, is very trying, and so we assume 

 that there are things in nature. These things are separated 

 from each other, at the same instant of time, by intervals of 

 space, while they are separated from each other, in the same 

 space, by intervals of time. Thus we have something to lean up 

 against and sustain ourselves in this rather difficult process of 

 apprehending nature. The things that we regard as existing 

 apart from each other in space and time are electrons. But 

 just yet that is rather inconvenient, and so we regard our natural 

 things as atoms and molecules in motion in an arbitrary three 

 dimensional space and an arbitrary one-dimensional time. • 



