Mr Glover on Forms of Induction. 127 



logically certain : " Nam inductio fit ex omnibus singularibus."* 

 But the examples of induction with which he was acquainted, 

 were cases in which it is requisite to examine every instance be- 

 longing to a law before the due amount of evidence can be col- 

 lected. As the subject is placed in an exceedingly favourable 

 light by some sentences of Gassendi, we shall take the liberty of 

 quoting those : — 



" Etenim ipsa quoque inductio sj^llogismus reipsa est; et quadamtenus 

 quidem mediiE inter enthymena et gradationem conditionis, — * • * hie cum 

 dicitur, v. c. oinne animal gressile vivit, omne item volatile vivit, omne etiani 

 natatile, omne reptile, omne zooph3'tum ; igitiir omne animal vivit ; as^mp- 

 tiones hinc plures sunt, justa generaliores species gradus animalis coUectte, 

 et quasi in unam coadunalae, quam ista propositio intelligatur praecedere, 

 omne animal aut gressile, aut volatile, aut natatile, aut reptile, aut zooph)'- 

 tum est. 



" Scilicet, nisi hujusmodi propositio supponeretur, suppressare licet, subin- 

 telligeretur tamen, consequentioris vis nulla foret ; cum si prseter enumerata 

 existeret aliud quodpiam animal, conclusio evaderet falsa. 



" Unde et licet intelligi, debere induclionem, ut legitima sit, continere 

 omnium specierum, partiumve enumerationem ; ne si una qusepiam deficiat, 

 ea exceptionem facial, probationemque labefactet. Quanquam, quia ut su- 

 perius semel, iterumque monuimus, difficile plerumque, aut impossibUe 

 etiam est enumerationem omnium fieri, dici, aliquibus enumeratio, solet, 

 quod JLucretius, et Horatius, csetera de genera hoc ; supponendo videlicet, 

 prater membra enumerata occurrere nullum, quod secus se habeat."-t- 



He goes on to say, that there maybe an induction, concluding 

 in the negative, as well as an induction concluding in the affir- 

 mative. Except the error of supposing induction to be a species 

 of syllogism,| the above passages give a sufficient notion of the 

 opinions entertained at present with regard to the mode of pro- 

 cedure proper in induction, in order that the evidence may 



" De Inductione (Analjt. Prior, lib. 2, c. 23.) 



t Institutionum Logic. P. 3, Canon 11. 



;); An error not confined to this writer, as is shewn in a very powerful ar- 

 ticle in the Edinburgh Review, vol. Ivii. ; but common to him with most au- 

 thors on logic ; although not participated in by Aristotle, according to the 

 reviewer. We find Aristotle say, that " quodam modo opponitur inductio 

 syllogisnio." And in his chapter on Induction, he seems to assign distinctly 

 the province of demonstrative reasoning to syllogism, and the discovery of 

 physical truth to induction. AVlien he says that syllogism is " natura prior 

 et notior," he probably alludes to reasoning from an obscure and unanalyzed 

 whole to its parts. 



