9 3 CLASSES OF IDEAS. Sect. XV. 2. u 



attributed to memory, as we talk of memorandum-rings, and 

 tie a knot on our handkerchiefs to brhig fomething into our 

 minds at a dillance 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 (hewn to belong 

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



II. Laftly, the method already -plained of claffing ideas into 

 thofe excited by irritation, fenfation, volition, or affociation, wc 

 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 {hall here recapitulate. 



1. Irritative ideas are thofe, which are preceded by irritation, 

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

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

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

 termed perception, in the latter it is termed fimply an irritative 

 idea. 



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

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

 dreams or reveries, this 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 fing a tune we are accuf- 

 tomed to ; this is called fuggeftion. 



III. 1 . Perceptions fignify thofe ideas, which are preceded by 

 irritation and fucceeded 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 clafTes of ideas, either thofe 

 which are preceded by voluntary exertion, or thofe which are 

 fuggefled by their affociations 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 wc re-excited the ideas, in which they differ, it is called 

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

 it is called comparing. 



Invention is an operation of the fenforium, by which we 



voluntarily 



