INDUCTIONS IMPROPERLY SO CALLED. 



193 



is a new element added to the com- 

 bination by the very act of thought 

 by which they are combined. . . . 

 When the Greeks, after long observing 

 the motions of the planets, saw that 

 these motions might be rightly con- 

 sidered as produced by the motion of 

 one wheel revolving in the inside of 

 another wheel, these wheels were crea- 

 tions of their minds, added to the 

 facts which they perceived by sense. 

 And even if the wheels were no longer 

 supposed to be material, but were re- 

 duced to mere geometrical spheres or 

 circles, they were not the less pro- 

 ducts of the mind alone, — something 

 additional to the facts observed. The 

 same is the case in all other dis- 

 coveries. The facts are known, but 

 they are insulated and unconnected, 

 till the discoverer supplies from his 

 own store a principle of connection. 

 The pearls are there, but they will 

 not hang together till some one pro- 

 vides the string." 



Let me first remark that Dr. Whe- 

 well, in this passage, blends together, 

 indiscriminately, examples of both 

 the processes which I am endeavour- 

 ing to distinguish from one another. 

 When the Greeks abandoned the 

 supposition that the planetar}' mo- 

 tions were produced by the revolu- 

 tions of material wheels, and fell 

 back upon the idea of "mere geo- 

 metrical spheres or circles," there 

 was more in this change of opinion 

 than the mere substitution of an 

 ideal curve for a physical one. There 

 was the abandonment of a theory, 

 and the replacement of it by a mere 

 description. No one would think of 

 calling the doctrine of material wheels 

 a mere description. That doctrine 

 was an attempt to point out the 

 force by which the planets were 

 acted upon, and compelled to move 

 in their orbits. But when, by a 

 great step in philosophy, the mate- 

 riality of the wheels was discarded, 

 and the geometrical forms alone re- 

 tained, the attempt to account for 

 the motions was given up, and what 

 was left of the theory was a, mere 



description of the orbits. The 

 tion that the planets were carried 

 round by wheels revolving in the 

 inside of other wheels, gave place to 

 the proposition that they moved in 

 the same lines which would be traced 

 by bodies so carried : which was a 

 mere mode of representing the sum 

 of the observed facts ; as Kepler's 

 was another and a better mode of 

 representing the same observations. 



It is true that for these simply 

 descriptive operations, as well as for 

 the erroneous inductive one, a con- 

 ception of the mind was required. 

 The conception of an ellipse must 

 have presented itself to Kepler's mind 

 before he could identify the planetary 

 orbits with it. According to Dr. 

 Whewell, the conception was some- 

 thing added to the facts. He ex- 

 presses himself as if Kepler had put 

 something into the facts by his mode 

 of conceiving them. But Kepler did 

 no such thing. The ellipse was in 

 the facts before Kepler recognised it ; 

 just as the island was an island before 

 it had been sailed round. Kepler did 

 not put what he had conceived into 

 the facts, but saw it in them. A con- 

 ception implies, and corresponds to, 

 something conceived : and though the 

 conception itself is not in the facts, 

 but in our mind, yet if it is to convey 

 any knowledge relating to them it 

 must be a conception of something 

 which really is in the facts, some 

 property which they actually possess, 

 and which they could manifest to our 

 senses if our senses were able to take 

 cognisance of it. If, for instance, the 

 planet left behind it in space a visible 

 track, and if the observer were in a 

 fixed position at such a distance from 

 the plane of the orbit as would en- 

 able him to see the whole of it at 

 once, he would see it to be an ellipse ; 

 and if gifted with appropriate instru- 

 ments and f)Owers of locomotion, he 

 would prove it to be such by measur- 

 ing its different dimensions. Nay, 

 further : if the track were visible, and 

 he were so placed that he could see 

 all parts of it in succession, but not 



