346 ' INDUCTION. 



of this magnitude are not made, the character of the solutions which are 

 given or sought of pai'ticular classes of phenomena, often involves such 

 conceptions of what constitutes explanation, as would render the notion of 

 explaining all phenomena whatever by means of some one cause or law, 

 perfectly admissible. 



§ 2, It is, therefore, useful to remark that the ultimate Laws of Nature 

 can not possibly be less numerous than the distingurshable sensations or 

 other feelings of our nature; those, I mean, which are distinguishable 

 from one another in quality, and not merely in quantity or degree. For 

 example : since there is a phenomenon siii generis, called color, which our 

 consciousness testifies to be not a particular degree of some other phenom- 

 enon, as heat or odor or motion, but intrinsically unlike all others, it fol- 

 lows that there are ultimate laws of color; that though the facts of color 

 may admit of explanation, they never can be explained from laws of heat 

 or odor alone, or of motion alone, but that, however far the explanation may 

 be carried, there will always remain in it a law of color. I do not mean 

 that it might not possibly be shown that some other phenomenon, some 

 chemical or mechanical action, for example, invariably precedes, and is the 

 cause of, every phenomenon of color. But though this, if proved, would 

 be an important extension of our knowledge of nature, it would not explain 

 how or why a motion, or a chemical action, can produce a sensation of 

 color; and, however diligent might be our scrutiny of the phenomena, 

 whatever number of hidden links we might detect in the chain of causa- 

 tion terminating in the color, the last link would still be a law of color, not 

 a law of motion, nor of any other phenomenon whatever. Nor does this 

 observation apply only to color, as compared with any other of the great 

 classes of sensations ; it applies to every particular color, as compared with 

 others. White color can in no manner be explained exclusively by the 

 laws of the production of red color. In any attempt to explain it, we can 

 not but introduce, as one element of the explanation, the proposition that 

 some antecedent or other produces the sensation of white. 



The ideal limit, therefore, of the explanation of natural phenomena (to- 

 ward which as toward other ideal limits we are constantly tending, with- 

 out the prospect of ever completely attaining it) would be to show that 

 each distinguishable variety of our sensations, or other states of conscious- 

 ness, has only one sort of cause; that, for example, whenever we perceive 

 a white color, there is some one condition or set of conditions which is al- 

 ways present, and the presence of which always produces in us that sensa- 

 tion. As long as there are several known modes of production of a phe- 

 nomenon (several different substances, for instance, which have the property 

 of whiteness, and between which we can not trace any other resemblance) 

 so long it is not impossible that one of these modes of production may 

 be resolved into another, or that all of them may be resolved into some 

 more general mode of production not hitherto recognized. But when the 

 modes of production are reduced to one, Ave can not, in point of simplifica- 

 tion, go any further. This one may not, after all, be the ultimate mode ; 

 there may be other links to be discovered between the supposed cause and 

 the effect ; but we can only further resolve the known law, by introducing 

 some other law hitherto unknown, which will not diminish the number of 

 ultimate laws. 



In what cases, accordingly, has science been most successful in explaining 

 phenomena, by resolving their complex laws into laws of greater simplicity 



