ix THE DOCTRINE OF IMMORTALITY 197 



properly no simplicity in it at one time, nor identity in dif- 

 ferent, whatever natural propension we may have to imagine 

 that simplicity and identity. The comparison of the the- 

 atre must not mislead us. They are the successive per- 

 ceptions 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 per- 

 son." (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. 



