9 CLASSES OF IDEAS. SECT. XV. 2. i. 



attributed to memory, as we talk of memoranda m-ring-s, and 

 tie a knot on our handkerchiefs to bring fomething into our 

 minds at a diftance of time. And a fchool-boy who can repeat 

 a thoufand unmeaning lines in Lilly's Grammar^ is faid to have 

 a good memory. But thefe have been already fhewn to belong 

 to the clafs of aflbciation ; and are termed ideas of fuggeftion. 



II. Laitly, the method already explained of clafling ideas into 

 thofe excited by irritation, fenfation, volition, or aflbciation, we 

 hope will be found more convenient both for explaining the 

 operations of the mind, and for comparing them with thofe of 

 the body ; and for the illuftration and the cure of the difeafes of 

 both, and which we fhall here recapitulate. 



i Irritative ideas are thofe, which are preceded by irritation, 

 which is excited by objefts external to the organs of fenfe : as 

 the idea of that tree, which either I attend to, or which I (hun 

 in walking near it without attention, In the former cafe it is 

 termed perception, in the latter it is termed {imply an irritative 

 idea. 



2. Sensitive ideas are thofe, which are preceded by the fen- 

 fation of pleafure or pain ; as the ideas, which conflitute our 

 dreams or reveries ; his is called imagination. 



3. Voluntary ideas are thofe, which are preceded by voluntary- 

 exertion, as when I repeat the alphabet backwards : this is call- 

 ed recollection. 



4. AiTociate ideas are thofe, which are preceded by other 

 ideas or mufcular motions, as when we think over or repeat the 

 alphabet by rote in its ufual order ; or (ing a tune we are accuf- 

 tomed to : this is called fuggefbion. 



III. i. Perceptions fignify thofe ideas, which are preceded by 

 irritation and iucceeded by the fenfation of pleafure or pain, 

 for whatever excites our attention interefts us ; that is, it is ac- 

 companied with pleafure or pain ; however flight may be the 

 degree or quantity of either of them. 



The word memory includes two clafles of ideas, either thofe 

 which are preceded by voluntary exertion, or thofe which are 

 fuggeiled by their aflbciations with other ideas. 



2. Reafoning is that operation of the fenforium, by which we 

 excite two or many tribes of ideas : and then re excite the ideas, 

 in which they differ, or correfpond. If we determine this differ- 

 ence, it is called judgment : if we in vain endeavour to deter- 

 mine it, it is called doubting. 



If we re-excite the ideas in which they differ, it is called 

 diftinguifhing. If we re-excite thofe in which they correfpond, 

 it is called comparing. 



3. Invention is an operation of the fenforium, by which we 



voluntarily 



