3 io POPULAR SCIENCE MONTHLY 



THE VATATE OF SCIENCE 



By M. H. POINCARE 



MEMBER OF THE INSTITUTE OF FRANCE 



Chapter II. The Measure of Time 

 I. 



So long as we do not go outside the domain of consciousness, the 

 notion of time is relatively clear. Not only do we distinguish without 

 difficulty present sensation from the remembrance of past sensations or 

 the anticipation of future sensations, but we know perfectly well what 

 we mean when we say that, of two conscious phenomena which we 

 remember, one was anterior to the other; or that, of two foreseen con- 

 scious phenomena, one will be anterior to the other. 



When we say that two conscious facts are simultaneous, we mean 

 that they profoundly interpenetrate, so that analysis can not separate 

 them without mutilating them. 



The order in which we arrange conscious phenomena does not admit 

 of any arbitrariness. It is imposed upon us and of it we can change 

 nothing. 



I have only a single observation to add. For an aggregate of sensa- 

 tions to have become a remembrance capable of classification in time, 

 it must have ceased to be actual, we must have lost the sense of its 

 infinite complexity, otherwise it would have remained present. It must, 

 so to speak, have crystallized around a center of associations of ideas 

 which will be a sort of label. It is only when they thus have lost all 

 life that we can classify our memories in time as a botanist arranges 

 dried flowers in his herbarium. 



But these labels can only be finite in number. On that score, 

 psychologic time should be discontinuous. Whence comes the feeling 

 that between any two instants there are others? We arrange our 

 recollections in time, but we know that there remain empty compart- 

 ments. How could that be, if time were not a form preexistent in 

 our mind? How could we know there were empty compartments, if 

 these compartments were revealed to us only by their content? 



II. 

 But that is not all; into this form we wish to put not only the 

 phenomena of our own consciousness, but those of which other con- 

 sciousnesses are the theater. But more, we wish to put there physical 

 facts, these / know not what with which we people space and which no 



