SECTION 23 GENERALISATION. 359 



Sub-Conclusion, we discern that since animal groups and in- 

 dividuals virtually do not vary so far as cultural characteristics 

 are concerned, human groups and individuals should likewise 

 be assumed virtually not to vary congenitally in this respect. 

 Consequently, instead of the theory of natural selection ex- 

 pressly demanding that human groups and individuals should 

 markedly vary, we discover that it expressly demands they 

 should remain unaltered. Similarly the theory of radio-acti- 

 vity suggests now that instead of the earth gradually cooling, 

 as was surmised until recently, it is most probably growing 

 hotter. Astronomy harbours such a contradiction. "The moon 

 at its rising and setting appears much larger than when high 

 up in the sky. This is, however, a mere erroneous judgment ; 

 for when we come to measure its diameter, so far from finding 

 our conclusion borne out by fact, we actually find it to measure 

 materially less." (Herschel, Discourse, [72.].) 



183. (d} and (e) COMMON AND DISPARATE.- A. double 

 aspect should also be recognised: there may be no incompati- 

 bility between the principle of relativity and the law of the 

 propagation of light; nitrifying organisms abstract nitrogen 

 from the air, but certain bacteria reverse the process; certain 

 animals may be at one time positively, and at another time 

 negatively, heliotropic ; defects or virtues in one civilisation may 

 be present also in another ("six of the one and half a dozen of 

 the other", says the accepted proverb); an unfavourable rate 

 of exchange discourages buying and a favourable one selling; 

 some States succeed in one way, and some in an opposite or 

 different way, in dealing with certain social problems; certain 

 culturally backward peoples possess certain simian characteristics 

 which Europeans are without, but Europeans have other simian 

 characteristics which culturally backward peoples do not possess ; 

 bracing winds build up one man's constitution, wreck another 

 man's, and leave a third man's constitution unaffected ; excite- 

 ment now benefits and now injures a person; not only may 

 fatigue be induced by injecting into an animal the toxin pro- 

 duced by fatigue, but possibly fatigue may be removed by 

 introducing the complementary anti-toxin; binocular vision com- 

 monly emphasises the third dimension, yet monocular vision 

 sometimes exercises the same effect, as looking at a good land- 

 scape picture with one eye closed; the plants which abstract 

 carbonic acid from the air, also abstract oxygen; the earth 

 attracts the unsupported stone, but the stone also attracts the 

 earth ; two unrelated individuals bear the same name ; owing 

 to unequal digestibility, a certain food of a higher nutritive 

 value may be less nutritious than a certain other food of a 

 lower nutritive value. If it be argued that social life betokens 

 a sign of superiority and of advantage in the evolutionary 

 struggle, we may reason as follows: "We are naturally much 

 impressed by the habits of social bees, but we may notice that 



