THE CAUSATION OF DISEASE. 2\J 



part in determining whether or not an individual shall leave 

 offspring. Some are so mentally constituted as to prefer single 

 life, be it from constitutional coldness, the lack of domestic 

 instinct, the love of a restless and roving life (which is a relic 

 of the past), or what not. This class tends to be weeded out, 

 members of it leaving few or no offspring. Again, the sober, 

 steady, persevering man is better able to support a wife, and 

 is, therefore, more likely to marry, and to transmit these 

 qualities to posterity, than an individual possessing the oppo- 

 site characteristics. Unfortunately, this rule does not apply 

 with any great force to the lower classes, whose fruitfulness 

 seems to be in direct ratio to their extravagance and impru- 

 dence. Nevertheless, as I have already pointed out, although 

 the poor are very prolific, this class stands on the whole less 

 chance of handing down offspring to remote posterity, for in 

 larg9 towns the E of the poor is the " necessarily fatal," and 

 even in the country the comparatively wealthy stand a better 

 chance of rearing a numerous progeny than the very poor. 



But over and above this weeding- out of criminals, of those 

 who, from other mental causes, do not marry, and, finally, of 

 those who, although married, stand, on account of poverty, 

 less chance of rearing a healthy offspring which shall con- 

 tinue fruitful in a remote futurity, there is a terrific weeding- 

 out of those mentally tin fit to cope with their environment ; not 

 only of these who break the laws of the land, but of such as 

 voluntarily transgress the simple canons of health. Man, as 

 we have seen, differs very largely from the brutes in that he 

 possesses greater controlling power over his E. Now, if he 

 voluntarily places himself amid a disease-causing E, he may 

 be said to be incapable of coping with his E : it is not the 

 E that is so much at fault as himself. All individuals are 

 surrounded more or less by such pathogenic E's. Some avoid 

 them (for I am only speaking of such as are avoidable), others 

 plunge voluntarily into their midst. To recount, one by one, 

 the many ways in which individuals can thus damage their 

 health, were an endless task. They consist, for the most part, 

 of excesses, whether of eating, drinking, or sexuality — de- 

 bauchery, in fact. Individuals leading such debauched lives 

 tend to be weeded out, it may not, indeed, be in the first 



