INDUCTION IN ITS VARIOUS SENSES 35 



But another leading Scholastic, Duns Scotus, has analysed 

 with a good deal of precision the procedure by which the general 

 ization is effected. When a phenomenon occurs repeatedly under 

 the influence of a cause that is not free, we must conclude, he 

 teaches, that the effect in question has a &quot; natural &quot; connexion 

 with the cause. . . . For it is impossible that a necessary cause 

 produce the same effect regularly, unless it is determined by its 

 natural tendency its directive principle or form, as he calls it to 

 produce this effect. The effect must spring from the nature of 

 that cause and not from any accidental, concomitant agencies ; 

 for accidental agencies do not produce regular effects. And that 

 any such regular series of effects is due to the nature of a certain 

 cause, we know from experience : because we have seen this cause 

 followed by these effects, when acting now in one set of conditions, 

 again in a different set, and altogether in many varieties of cir 

 cumstances, 1 Thus, Scotus points out as the rational, self- 

 evident basis of induction, the judgment that what REGULARLY 

 results front the action of NON-FREE causes cannot be the result 

 of mere CHANCE, but must have a necessary connexion with the 

 NATURE of those causes ; and he furthermore points to the neces 

 sity of varying our experiences, in order to separate, from the 

 changing and accidental circumstances that accompany the ap 

 pearance of the phenomenon in question, the one agency or group 

 of agencies on which it is really dependent, which forms its real 

 cause : a plain application of the modern Method of Agreement. 



Why, then, it may be asked, did the Scholastics of the Middle Ages, if 

 they knew the theory of scientific induction, and the principle underlying it, not 

 proceed to apply the method, and so anticipate by centuries the wonderful 



1 &quot; De cognitis per experientam dico, quod licet experientia non habeatur de om 

 nibus singularibus, sed de pluribus, nee quod semper, sed quod pluries ; tamen 

 expertus infallibiliter novit, quod ita est, et quod semper et in omnibus ; et hoc per 

 istam propositionem quiescentem in anima : QUIDQUID EVENIT UT IN PLURIBUS AB 



ALIQUA CAUSA NON LIBERA, EST EFFECTUS NATURALIS ILLIUS CAUSAE. Quae pro- 



positio nota est intellectui, licet accepisset terminos ejus a sensu errante, quia causa 

 non libera non potest producere ut in pluribus effectum, ad cujus oppositum ordinatur, 

 vel ad quern ex forma sua non ordinatur . . . sed causa casualis ordinatur adprodu- 

 cendum oppositum effectus naturalis, vel non ad istum producendum, ergo nihil est 

 causa casualis respectu effectus frequenter producti ab eo, et ita si non est libera, est 

 naturalis. . . . Quod autem iste effectus evenit a tali causa producente ut in pluribus, 

 hoc acceptum est per experientiam ; quia inveniendo nunc talem naturam cum tali 

 accidenie. nunc cum tali, inventum est, quod, quantumcumque esset diversitas acci- 

 dentium talium, semper istam naturam sequebatur talis effectus. Ergo non per 

 aliquod accidens, per accidens illius naturae, sed per naturam ipsam in se conse- 

 quitur tallis effectus&quot; (In. /. Sent. dist. iii., Q. iv, 9). 



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