PERSONAL IDENTITY. 89 



Identical strictly means " one and the same ; " and if 

 it were tied down to its strictest usage, it would indeed 

 follow very logically, as we have said already, that no 

 such thing as personal identity is possible, but that the 

 case actually is as Bishop Butler has supposed his 

 opponents without qualification to maintain it. In 

 common use, however, the word " identical " is taken to 

 mean anything so like another that no vital or essential 

 differences can be perceived between them, as in the 

 case of two specimens of the same kind of plant, when 

 we say they are identical in spite of considerable in- 

 dividual differences. So with two impressions of a 

 print from the same plate ; so with the plate itself, 

 which is somewhat modified with every impression 

 taken from it. In like manner " identity " is not held 

 to its strict meaning absolute sameness but is pre- 

 dicated rightly of a past and present which are now 

 very widely asunder, provided they have been con- 

 tinuously connected by links so small as not to give 

 too sudden a sense of change at any one point ; as, for 

 instance, in the case of the Thames at Oxford and 

 Windsor or again at Greenwich, we say the same river 

 flows by all three places, by which we mean that much of 

 the water at Greenwich has come down from Oxford 

 and Windsor in a continuous stream. How sudden a 

 change at any one point, or how great a difference 

 between the two extremes is sufficient to bar identity, 

 is one of the most uncertain things imaginable, and 

 seems to be decided on different grounds in different 

 cases, sometimes very intelligibly, and again at others 

 arbitrarily and capriciously. 



