132 INTRODUCTION 



all souls, from the soul of the pebble to that of the 

 angel, as Leibniz puts it in his correspondence with 

 J. Bernouilli 1 . The characteristics of these petites 

 perceptions, which prevent us from being clearly aware of 

 them, are, he tells us 2 , their smallness, their number, 

 or their individual indistinctness. And by means of 

 them he explains such psychological phenomena as our 

 ceasing to be aware of the sound of a mill or a waterfall 

 when we have become accustomed to it. The perceptions 

 are still there, but ' having lost the attractions of novelty, 

 they are not strong enough to claim our attention and 

 memory, which are directed to more interesting objects. 

 For all attention requires memory ; and often, when we 

 are not, so to speak, warned and directed to take notice 

 of certain of our own present perceptions, we let them 

 pass without reflexion, and even without observing 

 them ; but if some one immediately afterwards draws our 

 attention to them, and speaks to us, for instance, of some 

 noise that has just been heard, we recall it to ourselves 

 and perceive that a moment ago we had some conscious- 

 ness of it. Thus there were perceptions of which we 

 were not aware at the time, apperception arising in this 

 case only from our attention having been drawn to them 

 after some interval, however small V The petites perccp- 



1 G. Math. iii. 560. 



_ a New Essays, Introduction, p. 370. Cf. bk. ii. ch. 9, i (E. 233 a ; 

 G. v. 121) : 'We ourselves have also petites perceptions, of which we 

 are not conscious in our present state. It is true that we might 

 quite well be conscious of them and reflect upon them, were we 

 not prevented by their multitude, which distracts our mind, or if 

 they were not effaced or rather obscured by greater ones. ... I 

 should prefer to distinguish between perception and apperception. 

 For instance, the perception of light and colour, of which we have 

 apperception [are conscious] is made up of a quantity of petites 

 perceptions, of which we have no apperception [are not conscious] ; 

 and a noise, of which we have perception but of which we take 

 no notice, becomes apperceptible by a small addition or increase. 

 For if what precedes had no effect upon the soul, this little addition 

 would have none either, and no more would the whole have any.' 



3 New Essays, Introduction, p. 371. Cf. Nouveaux Essais, bk. ii. 

 ch. i, ii (E. 224 a ; G. v. 103) : 'We think of a number of things 

 at once, but we take notice only of the thoughts which are most 



