BERGSON S CONCEPTION OF DURATION 203 



for any moment of our duration. Descartes built up an "instantane- 

 ous physics which was intended for a universe the whole duration of 

 which might as well be confined to the present moment." Spinoza 

 assumed that the "indefinite duration of things was all contained in a 

 single moment, which is eternity." Everywhere we find the desire 

 to estabHsh a relation of logical necessity between cause and effect, 

 to do away with active duration, and "to substitute for apparent 

 causality a fundamental identity." The more cause and effect are 

 bound up together the more we try to put the effect in the cause 

 itself and thus eUminate the effect of duration. We do not behave 

 today as we did yesterday under the same conditions because we 

 change, we endure. The more we believe in causality the more 

 inclined we are to think of duration as subjective, and that things 

 do not endure like ourselves. That the prefiguring of the future in 

 the present is easily conceived under a mathematical form is due to a 

 certain conception of duration which is familiar to common-sense. If 

 we accept the dynamic conception of causaHty, we ascribe to things 

 a duration like our own, whatever may be the nature of duration. 

 The principle of causaUty involves two contradictory conceptions 

 of duration, each of these by itself safeguards freedom; but taken 

 together they destroy it. Sometimes all phenomena, physical and 

 psychical, are regarded as ending in the same way that we do. Some- 

 times, on the other hand, duration is regarded as the form of conscious 

 states, and in this case things no longer endure as we do. 



Now, each of these two hypotheses when taken by itself safeguards human 

 freedom ; for the first would lead to the result that even the phenomena of Nature 

 are contingent, and the second, by attributing the necessary determination of 

 physical phenomena to the fact that things do not endure as we do, invites us to 

 regard the self, which is subject to duration, as a free force.' 



The trouble is that we take the principle of causality in both 

 senses at the same time. 



Sometimes we think of the regular succession of physical phenomena and of 

 the kind of inner effort by which one becomes another; sometimes we fix our mind 

 on the absolute regularity of these phenomena, and from the idea of regularity 

 we pass by imperceptible steps to that of mathematical necessity, which excludes 

 duration understood in the first way." 



'Ibid., p. 21$. •Ibid., p. 216. 



