130 PLYMOUTH INSTITUTION. 



pose of reasoning. To accomplish this desideratum it was thought 

 necessary that all accurate reasoners should enter into certain meta- 

 physical investigations, relative to the theory of simple and complex 

 ideas, in order to become acquainted with the laws which regulate 

 their natural association and multifarious combinations, as an indis- 

 pensable preliminary to the right use of those conventional terms by 

 which all ideas are arbitrarily denoted. A complete analysis must 

 therefore be made of the operations of the understanding, as it pro- 

 gresses from mere perception, to the exercise of judgment, and the 

 more extended efforts of ratiocination : it must be ascertained by 

 what steps the mind is led on by abstraction and generalization, to 

 apprehend and classify different objects as they present themselves 

 to its notice : and thus we shall be prepared, it is affirmed, to enter 

 into a just appreciation of the value and adequacy of a specific 

 mode of arranging our own thoughts in due order, and of educing 

 therefrom infallible conclusions. The lecturer then proceeded to 

 exhibit the general outlines of this plan, and, in a few of its more 

 striking features, to enter somewhat into detail. He explained the 

 celebrated doctrines of the CATAGOUIES, or PREDICAMENTS, invented 

 by Archytas, for the purpose of reducing all possible phenomena 

 under distinct heads, that we might thereby readily perceive their 

 nature and mutual relation. From the arbitrary assumption of these 

 divisions, their number was of course indefinite, but it was thought 

 convenient by the early logicians to limit them to ten : their disci- 

 ples, however, have presumed to amend, curtail, or enlarge them, to 

 such a degree, that the whole scheme is in danger of falling into 

 contempt. 



The next point requiring illustration was the distribution of 

 propositions into singular and universal : and here, though it 

 admitted that the leading distinctions are based on nature and truth, 

 still it was objected that the endless subdivisions according to quan- 

 tity, quality, particular, indefinite, affirmative, negative, conditional, 

 disjunctive, exclusive, exceptive, comparative, desitive, hypothetical, 

 were in many cases artificial, and in most perplexing and useless. Not- 

 withstanding the unfavourable opinion entertained by the Lecturer in 

 reference to these diverging ramifications, he felt it his duty to show 

 the manner in which they are imagined to be rendered available; and 

 he therefore displayed the logician's diagram of CONVERSION, which is 

 supposed to afford a practical test for proving the truth or falsity of 

 of any given proposition; leaving his hearers to judge for themselves 

 how lucidly it was calculated to effect the end for which it was 

 designed. Having now introduced a regularly constructed SYLLO- 



