INDUCTIONS IMPROPERLY SO CALLED. 367 



and the consequent facility of conceiving it and 

 reasoning about it : for it would not really be more 

 true than the other. Different descriptions, there- 

 fore, may be all true : but not, surely, different 

 explanations. The doctrine that the heavenly bodies 

 moved by a virtue inherent in their celestial nature ; 

 the doctrine that they were moved by impact, (which 

 led to the hypothesis of vortices as the only impelling 

 force capable of whirling bodies in circles,) and the 

 Newtonian doctrine, that they are moved by the 

 composition of a centripetal with an original projec- 

 tile force ; all these are explanations,, collected by 

 real induction from supposed parallel cases; and they 

 were all successively received by philosophers, as 

 scientific truths on the subject of the heavenly bodies. 

 Can it be said of these, as we said of the different 

 descriptions, that they are all true as far as they go ? 

 Is it not clear that one only can be true in any 

 degree, and the other two must be altogether false ? 

 So much for explanations : let us now compare dif- 

 ferent predictions : the first, that eclipses will occur 

 whenever one planet or satellite is so situated as to 

 cast its shadow upon another ; the second, that they 

 will occur whenever some great calamity is impending 

 over mankind. Do these two doctrines only differ in 

 the degree of their truth, as expressing real facts 

 with unequal degrees of accuracy? Assuredly the 

 one is true, and the other absolutely false. 



In every way, therefore, it is evident that when 

 Mr. Whewell explains induction as the colligation of 

 facts by means of appropriate conceptions, that is, 

 conceptions which will really express them, he con- 

 founds mere description of the observed facts with 

 inference from those facts, and ascribes to the latter 

 what is a characteristic property of the former. 



