QN HUiMAN UNDERSTANDING. 



401 



proof or demonstration, for I have no nlore evidence of my existence by 

 calling up the ideas, I think, than I have before this proposition was con- 

 ceived. And hence the attempt not only fails, but could lead to no use 

 if it could stand its ground. 



Our knowledge of personal identity is derived from the same source^ 

 It ii INTUITIVE. This is a subject which has excited a great deal of learned 

 controversy, — and called forth many a different proof, or attempt at 

 proof, from the different disputants who have engaged in it. Mr. Locke 

 himself, with a singular deviation from the principles of his own system^ 

 lias fallen into a common error, and offered as a proof the idea of con- 

 sciousness. No proof, however, or attempt at proof, is more imperfect ; 

 for the identity often continues when the consciousness is interrupted, as in 

 sleep without dreaming, in apoplexy, catalepsy, drowning, and various 

 other cases ; and hence if identity were dependent on consciousness, the 

 same man in a dead sleep and out of it would be two or more different 

 persons. The truth is, that our knowledge of identity is intuitive ; the 

 two ideas, I am, and the two ideas / was, a combination of which con- 

 stitutes the more complex idea of personal identity, are ideas of necessary 

 connexion from the first moment the connexion can be formed ; and hence 

 they produce certain knowledge, and can have no proof; since there can 

 be no intermediate idea capable of possessing a closer connexion with 

 either proposition, and consequently fitted to enter between them. " Here 

 then," to adopt the language of Bishop Butler, whose reasoning upon this 

 subject bears a close resemblance to the present, " we can go no further,. 

 For it is ridiculous to attempt to prove the truth of those perceptions, 

 whose truth we can no otherwise prove tlian by other perceptions of ex- 

 actly the same kind with them, and which there is just the same ground, to- 

 suspect : or to attempt to prove the truth of our faculties, which can no 

 otherwise be proved than by the use or means of those very suspected fa- 

 culties themselves."* 



I may now advance a step further, and observe that in all cases in which- 

 the agreement or disagreement of two or more ideas can be immediately 

 perceived and compared together, our knowledge is of a hke kind, and 

 consequently approaches to intuitive ; although to other persons such ideas 

 may be very remote, and require a long chain of intermediate idea« to con- 

 nect or separate them, or prove their agreement or repugnancy. Thus I 

 know intuitively, or without going through the process, that the arc of a 

 circle is less than the entire circle ; that a circle itself is a line equi-distant 

 in every part of it from its centre ; that the three angles of a triangle are 

 equal to two right angles ; that the square of four is sixteen. No man, 

 however, can perhaps have any kind of knowledge at first sight upon any 

 of these subjects ; he cannot put the extreme ideas together in such a 

 manner as to perceive their agreement or disagreement, and he is not ac- 

 quainted with the intermediate ideas which are to compare them, and 

 prove their relation. If he could perceive that relation at first sight, he 

 would at first sight have intuitive knowledge upon the subject : and some 

 persons have a much more comprehensive power of this kind than others ; 

 for they can perceive and compare the relations of ideas both more readily 

 and more extensively. Euler was a striking example of this endowment, 

 in regard to the science of abstract quantities ; Jedediah Buxton appears 

 to have obtained a similar degree of intuitive knowledge in regard to the 



* Analogy of Religion, Natural and Revealed. Of Personal Identity, forming. Diss* i.- 



51 



