116 PART II SOME IMPORTANT METHODOLOGICAL TERMS. 



the principal appeal would be probably to the achievements 

 of the great masters (as representing the flood level of great 

 epochs) and to educated thought and feeling. 



As the interdependence, of facts obtrudes itself more and 

 more on the consciousness of men of science, they are less 

 and less inclined to seek for laws of nature or, what is their 

 equivalent, general facts to which no exception can be dis- 

 covered. 1 At the same time it is the earnest concern of science 

 to arrive at irreproachable statements, for only these can be 

 entirely relied on or fully utilised for deductive purposes. Such 

 statements should not be, however, platitudinarian, for to state 

 that gold is always yellow, the wind-lashed sea invariably 

 vocal, or that "air has weight", 2 would be puerile. Given, then, 

 a comprehensive and pregnant law established, we can defi- 

 nitely prove or disprove a statement by observing whether it 

 comports in all respects with the law. This is the highest 

 order of proof available at present and, strictly speaking, the 

 only unambiguous kind of proof. As Herschel declares: "The 

 grand and indeed only character of truth is its capability of 

 enduring the test of universal experience and coming unchanged 

 out of every possible form of fair discussion." (Discourse, [6.].) 

 Next in order follow the large working hypotheses in science 

 which represent provisional laws, and are employed as a staple 

 test. 



Although, of course, preferring irrefragable proof, the man 

 of science naturally accommodates himself to whatever degree 



1 "If I might impress any caution upon your minds, it is the utterly 

 conditional nature of all our knowledge the danger of neglecting the process 

 of verification under any circumstances; and the film upon which we rest, 

 the moment our deductions carry us beyond the reach of this great process 

 of verification. There is no better instance of this than is afforded by the 

 history of our knowledge of the circulation of the blood in the animal 

 kingdom until the year 1824. In every animal possessing a circulation at 

 all, which had been observed up to that time, the current of the blood was 

 known to take one definite and invariable direction. Now, there is a class 

 of animals called ascidians, which possess a heart and a circulation, and 

 up to the period of which I speak no one would have dreamt of questioning 

 the propriety of the deduction that these creatures have a circulation in 

 one direction; nor would anyone have thought it worth while to verify the 

 point. But in that year M. von Hasselt, happening to examine a transparent 

 animal of this class, found to his infinite surprise that after the heart had 

 beat a certain number of times it stopped, and then began beating the 

 opposite way, so as to reverse the course of the current, which returned 

 by-and-by to its original direction. I have myself timed the heart of these 

 little animals. I found it as regular as possible in its periods of reversal : 

 and I know no spectacle in the animal kingdom more wonderful than that 

 which it presents all the more wonderful that, to this day, it remains a 

 unique fact, peculiar to this class, among the whole animate world. At the 

 same time, I know of no more striking case of the necessity of the veri- 

 fication of even those deductions which seem founded in the widest and 

 safest inductions." (T. H. Huxlev, Twelve Lectures and Essays, ed. 1908, 

 pp. 13-14.) 



- Mill, Logic, bk. 3, ch. 4, 1. 



