186 INDUCTION. 



controverted point in regard to the fundamental axiom of induction, 

 until a more advanced period of our inquiry* At present it is of 

 more importance to understand thoroughly the import of the axiom 

 itself For the proposition, that the course of nature is uniform, pos- 

 sesses rather the brevity sviitable to popular, than the precision requi- 

 site in philosophical, language : its terms require to be explained, and 

 a stricter tlian their ordinary signification given to them, before the 

 truth of the assertion can be admitted. 



§ 2. Every person's consciousness assures him that he does not al- 

 ways expect uniforaiity in the course of events; he does riot always 

 believe that the unknown will be similar to the known, that the fu- 

 ture will resemble the past. Nobody believes that the succession of 

 rain and fine weather will be the same in every future year as in the 

 present. Nobody expects to have the same dreams repeated every 

 night. On the contrary, everybody mentions it as something extraor- 

 dinary, if the course of nature is constant, and resembles itself, in these 

 particulars. To look for constancy where constancy is not to be ex- 

 pected, as, for instance, that a day which has once brought good for- 

 tune 'will always be a fortunate day, is justly accounted superstition. 



The course of nature, in truth, is' not only uniform, it is also infi- 

 nitely various. Some phenomena are always seen to recur in the very 

 same combinations in which we met- with them at first; others seem 

 altogether capricious ; while some, which we had been accustomed to 

 regard as bound down exclusively to a particular set of combinations, 

 we unexpectedly find detached from some of the elements with which 

 we had hitherto found them conjoined, and united to others of quite 

 a contrary description. To an inhabitant of Central Africa, fifty years 

 ago, no fact probably appeared to rest upon more 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 

 unequivocal 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. During that long time, 

 mankind believed in an uniformity of the course of nature 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 ad- 

 mitted of The induction of the ancients has been well described by 

 -Bacon, under the name of"Inductio per enumerationem simplicem, 

 ubi non reperitur instantia contradictoria." It consists in ascribing 

 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, if it deserves the name, which is natural to the mind when unac- 

 customed to ■ scientific methods. The tendency, which some call an 

 instinct, and which others account for by association, to infer the fu- 

 ture from the past, the known from the unknown, is simply a habit of 

 expecting that what has been found true once or several times, 



* Infra, chap, xxi. 



