Limits 

 Logic 



SCIENTIFIC SIDE-LIGHTS 



404 



the orb of the planet can be seen through 

 this " crape-veil ring," as astronomers have 

 called it. PROCTOR Expanse of Heaven, p. 

 94. (L. G. & Co., 1897.) 



197O. LIMITS OF HUMAN THOUGHT 



Infinite Minuteness and Infinite Vastness 

 Baffle. What notion can you form of the 

 magnitude of such particles [the ulti- 

 mate particles of matter] ? The distances 

 of stellar space give us simply a be- 

 wildering sense of vastness, without leav- 

 ing any distinct impression on the mind; 

 and the magnitudes with which we have 

 here to do bewilder us equally in the op- 

 posite direction. We are dealing with in- 

 finitesimals, compared with which the test- 

 objects of the microscope are literally im- 

 mense. TYNDALL Fragments of Science, vol. 

 ii, ch. 8, p. 122. (A., 1897.) 



1971. The Infinity of 



Space. We cannot think of space as finite, 

 for wherever in imagination we erect a 

 boundary we are compelled to think of space 

 as existing beyond it. Thus by the incessant 

 dissolution of limits we arrive at a more or 

 less adequate idea of the infinity of space. 

 TYNDALL Fragments of Science, vol. i, ch. 1, 

 p. 3. (A., 1897.) 



1972. The Universe Un- 

 solved. I compare the mind of man to a 

 musical instrument with a certain range of 

 notes, beyond which in both directions ex- 

 ists infinite silence. The phenomena of mat- 

 ter and force come within our intellectual 

 range; but behind, and above, and around 

 us the real mystery of the universe lies un- 

 solved, and, as far as we are concerned, is 

 incapable of solution. TYNDALL Fragments 

 of Science, vol. ii, ch. 15, p. 393. (A., 1900.) 



1973. LIMITS OF PHYSICAL SCI- 

 ENCE Never Satisfies Soul Lunge consid- 

 ers the relation of Epicurus to the gods 

 subjective; the indication, probably, of an 

 ethical requirement of his own nature. We 

 cannot read history with open eyes or study 

 human nature to its depths, and fail to dis- 

 cern such a requirement. Man never has 

 been and he never will be satisfied with 

 the operations and products of the under- 

 standing alone; hence physical science can- 

 not cover all the demands of his nature. 

 TYNDALL Fragments of Science, vol. ii, ch. 

 9, p. 141. (A., 1897.) 



1974. LIMITS OF THE DOCTRINE 

 OF EVOLUTION Facts of this kind [per- 

 manence of various species from geologic 

 times] are undoubtedly fatal to any form of 

 the doctrine of evolution w r hich postulates 

 the supposition that there is an intrinsic 

 necessity, on the part of animal forms which 

 have once come into existence, to undergo 

 continual modification ; and they are as dis- 

 tinctly opposed to any view which involves 

 the belief that such modification as may 

 occur must take place at the same rate in 

 all the different types of animal or vege- 

 table life. The facts, as I have placed them 



before you, obviously directly contradict any 

 form of the hypothesis of evolution which 

 stands in need of these two postulates. 

 HUXLEY American Addresses, lect. ii, p. 38. 

 (A., 1898.) 



1975. LIMITS TO EDUCATIONAL 

 USE OF SCIENTIFIC THEORIES I have 

 never advocated the introduction of the 

 theory of evolution into our schools. I 

 should even be disposed to resist its intro- 

 duction before its meaning had been better 

 understood and its utility more fully recog- 

 nized than it is now by the great body of the 

 community. The theory ought, I think, to 

 bide its time until the free conflict of dis- 

 covery, argument, and opinion has won for 

 it this recognition. TYNDALL Fragments of 

 Science, vol. ii, ch. 15, p. 399. (A.^ 1900.) 



1976. LIMITS TO MAGNIFYING 

 POWER OF TELESCOPE The exceedingly 

 high magnifying powers employed by Her- 

 schel constituted a novelty in optical as- 

 tronomy to which he attached great impor- 

 tance. Yet the work of ordinary observation 

 would be hindered rather than helped by 

 them. The attempt to increase in this man- 

 ner the efficacy of the telescope is speedily 

 checked by atmospheric, to say nothing of 

 other difficulties. Precisely in the same pro- 

 portion as an object is magnified, the dis- 

 turbances of the medium through which it 

 is seen are magnified also. Even on the 

 clearest and most tranquil nights the air is 

 never for a moment really still. The rays of 

 light traversing it are continually broken by 

 minute fluctuations of refractive power 

 caused by changes of temperature and pres- 

 sure, and the currents which these engender. 

 With such luminous quiverings and waver- 

 ings the astronomer has always more or less 

 to reckon; their absence is simply a ques- 

 tion of degree; if sufficiently magnified, 

 they are at all times capable of rendering 

 observation impossible. CLERKE History of 

 Astronomy, pt. i, ch. 6, p. 137. (Bl., 1893.) 



1977. LINKS BETWEEN EURO- 

 PEAN AND AMERICAN SPECIES Bison 

 and Bear in New and Old World. If species 

 were in reality unconnected by common an- 

 cestors, then it would necessarily follow 

 that, as our knowledge of any group in- 

 creased, the separations between the differ- 

 ent species would become more and more 

 unmistakable. On the contrary, however, it 

 is a well-known fact that the difficult genera 

 become still more difficult as they are more 

 profoundly studied. If, indeed, we consider 

 existing forms only, no doubt the distinc- 

 tions between the greater number of species 

 are well marked, nor does any one expect to 

 find a living series of links between them. 

 The intermediate forms lived in Tertiary and 

 Quaternary times. Thus, directly we com- 

 mence to study the extinct forms, all the 

 convenient lines of separation gradually 

 thin out. ... To take only two cases 

 from the group of Quaternary mammalia, 



. . . the European and American bisons, 



