CHAPTER I 



OUTLINE— BIOLOGICAL METHODS 



The preceding pages give a certain aspect of the biological 

 problem and of its infinite complexity. We do not propose 

 to study in detail all biological problems, but only those which 

 may lead us progressively to the notion of time. If we seem 

 occasionally to deviate from our plan, it is because of the 

 necessity to show that, in spite of the difficulties encountered 

 and of the criticisms that can be made, certain modern methods 

 more than others are capable of helping the physiological 

 sciences, and even medicine, to progress rapidly. We hope 

 that the reader will be left with a truly optimistic outlook. 



In order that one may understand the general plan and 

 follow the directing thread between chapters which might 

 easily seem to possess no common link, we must state, at the 

 very beginning, that it is our purpose to introduce a new 

 concept of time, or, more exactly, to try to demonstrate that a 

 fundamental difference exists between physical time, the time 

 of the universe which flows at a uniform speed, and our 

 physiological, internal time, on which, so far, we had only very 

 vague ideas. We will show that this physiological time, which 

 has a beginning and an end, does not seem to flow at a uniform 

 rate. We will indicate the possibility of deriving from our 

 own organism a unit of time different from the classical one 

 derived from the rotation of the earth around its axis. We 

 will also attempt to show the quantitative discrepancy between 

 conceptual and physiological time. This will lead to an 

 explanation of the differences perceived in the appreciation 

 of the flow of time at the beginning and at the end of life, 

 and to a hypothesis on the relation existing between the two 

 times. 



Now, the point upon which we must insist at the beginning 

 of this book is that all these results are not based on hypotheses 

 but on experimental biological facts obtained by two different 



II 



