OBSERVATION AND DESCRIPTION. 387 



by measurement In the direction of the meridian, that the length on the 

 surface of the earth which subtends a given angle at its centre, dimin- 

 ishes as we recede from the equator and apju'oach the poles. Bui 

 these propositions, that the earth is glo!)ul;ir, and that it is an oblate 

 spheroid, assert, each of them, one individual fact; in its own nature 

 capable of being perceived by the senses when the requisite organs 

 and the necessary position are supposed, and only hot actually per- 

 ceived because these organs and that position are wanting. That 

 which, if the fact could have been seen, would have been called a de- 

 scription of the figure of the earth, may without impropriety be so 

 called when instead of being seen it is inferred. But we could not 

 ■vdthout impropriety call either of these assertions an induction from 

 facts respecting the earth. They arc not general propositions collected 

 from particular facts, but particular facts deduced from general prop- 

 ositions. They are conclusions obtained deductively, from premisses 

 originating in deduction ; but of these premisses some were not ob- 

 tained by observation of the earth, nor had any peculiar reference to it. 

 If, then, the truth respecting the figure of the earth is not an induc- 

 tion, why should the truth respecting the figure of the earth's orbit be 

 so ? Mr. Wliewell contends that it is ; although the two cases only 

 differ in this, that the form of the orbit was not, like the form of the 

 earth itself, deduced by ratiocination fi-om facts which were marks of 

 ellipticity, but was got at by boldly guessing that the path was an 

 ellipse, and finding afterwards, on examination, that the observations 

 were in harmony with the hy])othesis. Not only, according to Mr. 

 Wliewell, is this process of guessing and verifying our guesses induc- 

 tion, but it is the whole of induction : no other exposition can be given 

 of that logical operation. That he is \vi'ong in the latter assertion, the 

 whole of the preceding Book has, I hope, sufl'iciently proved ; and that 

 even the former of the two contains a large dose of eiTor with but a 

 small portion of truth, was attemjited to be shov n in the second chap- 

 ter of the same Book.* We ai-e now, however, prepared to go more 

 into the heart of the question than at that earlier period of our inquiry, 

 and a few words will, I think, suffice to dispel all remaining obscurity. 



§ 4. We observed, in the second chapter, that the proposition " the 

 earth moves in an ellipse," so far as it only serves for the colligation or 

 connecting together of actual observ^ations, (that is, as it only affirms 

 that the observed positions of the earth may be coiTectly represented 

 by as many points in the circumference of an imaginary ellipse,) is not 

 an induction, but a description : it is an induction only when it affirms 

 that the intermediate positions, of which there has been no direct 

 observation, would be found to correspond to the remaining points of 

 the same elliptic circumference. Now, although this real induction is 

 one thing, and the description another, we are in a VQry different con- 

 dition for making the induction after we have obtained the description, 

 and before it. For inasmuch as the description, like all other descrip- 

 tions, contains the assertion of a resemblance between the phenomenon 

 described and something else ; in pointing out something which the 

 series of observed places of a planet resembles, it points out something 

 in which the several places themselves agree. If the series of places 



♦ Supra, pp. 177-183. 



