LAWS OF NATURE. 193 



evidence of the truth of the better established law in which it is now 

 found to be included. We may have infeiTed, from historical evidence, 

 that the uncontrolled government of a monarchy, of au aristocracy, or 

 of the majority, will commonly be a tyranny : but we are entitled to 

 rely upon this generalization with much gi-eater assurance when it is 

 shown to be a corollary from still better established truths ; the 

 infirmity of human nature, and the impossibility of maintaining the 

 predominance of reason and conscience over the selfish propensities 

 by any means except such as the supposition of absolute power neces- 

 sarily excludes. It is at the same time obvious that even these great 

 facts in human nature derive an accession of evidence from the 

 testimony which history bears to the effects of despotism. The strong 

 induction becomes still stronger when a weaker one has been bound 

 up with it. 



On the other hand, if an induction conflicts with sti-onger inductions, 

 or with conclusions capable of being correctly deduced from them, then, 

 unless upon reconsideration it should appear that some of the stronger 

 inductions have been sti'etched too far, the weaker one must give way. 

 The opinion so long prevalent that a comet, or any other unusual ap- 

 peaiance in the heavenly regions, was the precursor of calamities to 

 mankind, or to those at least who witnessed it ; the belief in the vera- 

 city of the oracles of Delphi or Dodona ; the reliance on astrology, or 

 on the weather-prophecies in almanacs ; were doubtless inductions sup- 

 posed to be grounded on exj)erience : and faith in such delusions seems 

 quite capable of holding out against a gi-eat multitude of failures, pro- 

 vided it be nourished by a reasonable number of casual coincidences 

 between the prediction and the event. What has really put an end to 

 these insufficient inductions, is their inconsistency Avith the stronger in- 

 ductions subsequently obtained by scientific inquiry, respecting the 

 causes upon which terrestrial events really depend ; and where those 

 scientific truths have not yet peneti-ated, the same or similar delusions 

 still prevail. 



It may be affirmed as a general principle, that all inductions, whether 

 strong or weak, which can be connected together by a ratiocination, are 

 confirmatory of one another : while any which lead deductively to con- 

 sequences that are incompatible, become mutually each other's test, 

 showing that one or other must be given up, or, at least, more guard- 

 edly expressed. In the case of inductions which confirm each other, 

 the one which becomes a conclusion from ratiocination rises to at least 

 the level of certainty of the weakest of those fi-om which it is deduced; 

 while in general all are more or less increased in certainty. Thus the 

 Torricellian experiment, though a mere ease of three more general 

 laws, not only strengthened gi'eatly the evidence on which those laws 

 rested, but converted one of them (the weight of the atmosphere) fi-om 

 a doubtful generalization into one of the best-established doctrines in 

 the range of physical science. 



If, then, a sui-vey of the uniformities which have been ascertained to 

 exist in nature, should point out some which, as far as any human pur- 

 pose requires ceitainty, may be considered as absolutely certain and 

 absolutely universal ; then by means of these uniformities, we may be 

 able to raise raultitudas of other inductions to the same point in the 

 scale. For if we can show, with respect to any induction, that either 

 it must be true, or one of these certain and universal inductions must 

 Bb 



