196 HUME 



IX 



simplicity in it at one time, nor identity in different, whatever 

 natural propension we may have to imagine that simplicity 

 and identity. The comparison of the theatre must not mislead 

 us. They are the successive perceptions only that constitute 

 the mind ; nor have we the most distant notion of the place 

 where these scenes are represented, or of the materials of which 

 it is composed. 



" What then gives so great a propension to ascribe an 

 identity to these successive perceptions, and to suppose our- 

 selves possessed of an invariable and uninterrupted existence 

 through the whole course of our lives ? In order to answer 

 this question, we must distinguish between personal identity 

 as it regards our thought and imagination, and as it regards 

 our passions, or the concern we take in ourselves. The first 

 is our present subject ; and to explain it perfectly we must 

 take the matter pretty deep, and account for that identity 

 which we attribute to plants and animals ; there being a great 

 analogy betwixt it and the identity of a self or person." (I. 

 pp. 321, 322.) 



Perfect identity is exhibited by an object 

 which remains unchanged throughout a certain 

 time; perfect diversity is seen in two or more 

 objects which are separated by intervals of space 

 and periods of time. But, in both these cases, 

 there is no sharp line of demarcation between 

 identity and diversity, and it is impossible to say 

 when an object ceases to be one and becomes 

 two. 



When a sea-anemone multiplies, by division, 

 there is a time during which it is said to be one 

 animal partially divided; but after a while, it 

 becomes two animals adherent together, and the 

 limit between these conditions is purely arbitrary. 



