THE SELECTIVE FUNCTION OF RELIGION 361 



deterioration of its breed." Weak, timid and sequacious people 

 are not apt to be singled out for championing an unpopular cause, 

 or for defending what is considered a dangerous heresy. As 

 Lapouge remarks, "the persecuted are the superiors of their 

 persecutors"; they are apt to be the bold spirits who are willing to 

 brave personal danger for what they deem to be the truth. And 

 any country in which persecution has been vigorously carried on 

 for a long period of years cannot fail to lose a large proportion of 

 its best inheritance. 



Another dysgenic effect of religious selection is occasioned 

 by the celibacy of the clergy, which has grown up especially in the 

 Catholic church. Whatever may be said of the eugenic worth of 

 the women who take the veil, the men who become priests or 

 monks are above the average level of intellect. De Candolle in 

 his Histoire des sciences et des savants has cited a long list of 

 eminent men who were sons of Protestant clergymen and who 

 would not have been born had the institution of celibacy pre- 

 vailed in the Protestant churches. Of the 101 scientists who were 

 foreign members of the Academy of Sciences of Paris, 14, or over 

 13 per cent, were the sons of pastors. As Lapouge has pointed 

 out, a large proportion of eminent Jews are the sons of rabbis. 

 For a long time the church afforded one of the most promising 

 careers for men of exceptional intellect and character. To the 

 extent to which such men were committed to a celibate life, the 

 race suffered a loss of a valuable inheritance. Since the popula- 

 tion of the Catholic world has sustained this loss for many cen- 

 turies the cumulative effect of such a dysgenic process could 

 scarcely fail to be considerable. 



An effect of religion more widespread than the one just dis- 

 cussed is the tendency of the adherents of a particular cult to 

 marry only within the limits of their own fold. Thus arises what 

 Mr. Gulick would designate a form of "segregate breeding" 

 whose effect is analogous to that of geographical isolation. Any 

 isolated group tends, through continuous inbreeding, to become 

 more and more nearly homozygous in successive generations. 

 For this reason and perhaps others also, groups of a given species 



