504 



INDUCTION. 



quite a contrary description. To an 

 inhabitant of Central Africa fifty 

 years ago, no fact probably appeared 

 to rest on naore uniform experience 

 than this, that all human beings are 

 black. To Europeans not many years 

 ago, the proposition, All swans are 

 white, appeared an equally unequi- 

 vocal instance of uniformity in the 

 course of nature. Further experience 

 has proved to both that they were 

 mistaken ; but they had to wait fifty 

 centuries for this experience. Dur- 

 ing that long time, mankind believed 

 in an uniformity of the course of na- 

 ture where no such uniformity really 

 existed. 



According to the notion which the 

 ancients entertained of induction, the 

 foregoing were cases of as legitimate 

 inference as any inductions whatever. 

 In these two instances, in which, the 

 conclusion being false, the ground of 

 inference must have been insufficient, 

 there was, nevertheless, as much 

 ground for it as this conception of 

 induction admitted of. The induc- 

 tion of the ancients has been well 

 described by Bacon, under the name 

 of " Inductio per enumerationem sim- 

 plicem, ubi non reperitur instantia 

 contradictoria." It consists in ascrib- 

 ing the character of general truths 

 to all propositions which are true in 

 every instance that we happen to 

 know of. This is the kind of induc- 

 tion which is natural to the mind 

 when unaccustomed to scientific 

 methods. The tendency, which some 

 call an instinct, and which others 

 account for by association, to infer 

 the future from the past, the unknown 

 from the known, is simply a habit 

 of expecting that what has been found 

 true once or several times, and never 

 yet found false, will be found true 

 again. Whether the instances are 

 few or many, conclusive or inconclu- 

 sive, does not much affect the matter : 

 these are considerations which occur 

 only on reflection ; the unprompted 

 tendency of the mind is to generalise 

 its experience, provided this points all 

 in one direction ; provided no other 



experience of a conflicting character 

 comes unsought. The notion of seek- 

 ing it, of experimenting for it, of in- 

 terrogating nature (to use Bacon's ex- 

 pression) is of much later growth. 

 The observation of nature by uncul- 

 tivated intellects is purely passive: 

 they accept the facts which present 

 themselves, without taking the trouble 

 of searching for more : it is a superior 

 mind only which asks itself what facts 

 are needed to enable it to come to a 

 safe conclusion, and then looks out for 

 these. 



But though we have always a pro- 

 pensity to generalise from unvarying 

 experience, we are not always war- 

 ranted in doing so. Before we can be 

 at liberty to conclude that something 

 is universally true because we have 

 never known an instance to the con- 

 trary, we must have reason to be- 

 lieve that if there were in nature 

 any instances to the contrary, we 

 should have known of them. This 

 assurance, in the great majority of 

 cases, we cannot have, or can have 

 only in a very moderate degree. The 

 possibility of having it is the founda- 

 tion on which we shall see hereafter 

 that induction by simple enumeration 

 may in some remarkable cases amount 

 practically to proof.* No such assur- 

 ance, however, can be had on any of 

 the ordinary subjects of scientific in- 

 quiry. Popular notions are usually 

 founded on induction by simple enu- 

 meration ; in science it carries us but 

 a little way. We are forced to begin 

 with it ; we must often rely on it 

 provisionally, in the absence of means 

 of more searching investigation. But, 

 for the accurate study of nature, we 

 require a surer and a more potent in- 

 strument. 



It was, above all, by pointing out 

 theinsufiiciencyof /this rude and loose 

 conception of Induction that Bacon 

 merited the title so generally awarded 

 to him of Founder of the Inductive 

 Philosophy, The value of his own 

 contributions to a more philosophical 



* lufra, chap. xxi. xxii. 



