IMPROVING NATURAL KNOWLEDGE 25 



ill-clothed. The London of 1665 was such a city. The 

 cities of the East, where plague has an enduring dwelling, 

 are such cities. We, in later times, have learned some- 

 what of Nature, and partly obey her. Because of this 

 partial improvement of our natural knowledge and of 

 that fractional obedience, we have no plague; because 

 that knowledge is still very imperfect and that obedience 

 yet incomplete, typhoid is our companion and cholera our 

 visitor. But it is not presumptuous to express the belief 

 that, when our knowledge is more complete and our obe- 

 dience the expression of our knowledge, London will 

 count her centuries of freedom from typhoid and cholera, 

 as she now gratefully reckons her two hundred years of 

 ignorance of that plague which swooped upon her thrice 

 in the first half of the seventeenth century. 



Surely, there is nothing in these explanations which is 

 not fully borne out by the facts? Surely, the principles 

 involved in them are now admitted among the fixed 

 beliefs of all thinking men? Surely, it is true that our 

 countrymen are less subject to fire, famine, pestilence, 

 and all the evils which result from a want of command 

 over and due anticipation of the course of Nature, than 

 were the countrymen of Milton; and health, wealth, and 

 well-being are more abundant with us than with them? 

 But no less certainly is the difference due to the improve- 

 ment of our knowledge of Nature, and the extent to which 

 that improved knowledge has been incorporated with the 

 household words of men, and has supplied the springs of 

 their daily actions. 



Granting for a moment, then, the truth of that which 

 the'depreciators of natural knowledge are so fond of 

 urging, that its improvement can only add to the re- 

 sources of our material civilisation; admitting it to be 

 possible that the founders of the Royal Society them- 

 selves looked for no other reward than this, I cannot 



