8 MODERN SCIENCE : 



and as to the relative, why all we can say is that it does not exist (any 

 more than species exists) we cannot break up Nature so; it is not a thing 

 in Nature but in our own minds it is a view and a fiction. 



Again, let us take an example from Physics Boyle's law of the com- 

 pressibility of gases. This law states that, the temperature remaining 

 constant, the volume of a given quantity of gas is inversely proportional 

 to its pressure. It is a law which has been made a good deal of, and at 

 one time was thought to be true, i. e., it was thought to be a statement 

 of fact. A more extended and careful observation, however, shows that 

 it is only true under so many limitations, that, like the ellipse in Astron- 

 omy, it must be regarded as a convenient fiction and nothing more. It 

 appears that air follows the supposed law pretty well, but not by any 

 means exactly except within very narrow limits of pressure; other gases, 

 such as carbonic acid and hydrogen, deviate from it very considerably 

 some more than others, and some in one direction and some in the oppo- 

 site. It was found, among other things, that the nearer a gas was to its 

 liquefying point, the greater was the deviation from the supposed law, 

 and the conclusion was jumped at that the law was true for perfect gases 

 only. This idea of a perfect gas of course involved the assumption that 

 gases, as they get farther and farther removed from their liquefying point, 

 reach at last a fixed and stable condition, when no further change in 

 their qualites takes place at any rate for a very long time and Boyle's 

 law was supposed to apply to this condition. Since then, however, it 

 has been discovered that there is an ultra-gaseous state of matter, and on 

 all sides it is becoming abundantly clear that the change in the condition 

 of matter from the liquid state to the ultra-gaseous state is perfectly con- 

 tinuous through all modifications of liquidity and condensation and 

 every degree of perfection and imperfection of gassiness to the utmost 

 rarity of the fourth state. At what point, then, does Boyle's law really 

 apply ? Obviously it applies exactly at only one point in this long as- 

 cending scale at one metaphysical point and at every other point it is 

 incorrect. But no gas in Nature remains or can be maintained just at 

 one point in the scale of its innumerable changes. Consequently all we 

 can say is that out of the innumerable different states that gases are capa- 

 ble of, and the innumerable different laws of compressibility which they 

 therefore follow, we could theoretically find one state to which would 

 correspond the law of compressibility called Boyle's law; and that if we 

 could preserve a gas in that state (which we can't) Boyle's law really 

 would be true just for that case. In other words, the law is metaphysical. 

 It has no real existence. It is a convenient view or fiction, arising in 

 the first place out of ignorance, and only tenable as long as further obser- 

 vation is limited or wilfully ignored. 



This then is the Method of Science. It consists in forming a law or 

 statement by only looking at a small portion of the facts; then when the 

 other facts come in the law or statement gradually fades away again. 



