258 THE POPULAR SCIENCE MONTHLY. 



our brain to have, by a process of gradual improvement, become more 

 highly developed than the brain of the men of the stone age, 100,000 

 years ago ? And this brain, more perfect as it is by nature, has been, 

 at an early period of its life, subjected to innumerable unconscious 

 influences, and, later, to the conscious influences of education, which 

 render it in some sense incommensurable with the brain of those as yet 

 half-brute creatures. 



The instinct of causality, the questioning about the "why" of 

 things, which we greet in our children as a precious token of their 

 awakening human intelligence, is by some philosophers regarded as an 

 original characteristic of man's mind. Others hold even this to be a 

 derived faculty that it results from the faculty of generalization. So 

 much is certain, that, among men in a low grade of culture, the instinct 

 of causality is satisfied with reasons for things that hardly deserve the 

 name of reasons. Nothing, we are told by Charles Martins, strikes 

 one so forcibly in conversing with the inhabitants of the Sahara as 

 their lack of development in this respect. These people have no idea 

 of " cause " or of " law " as we understand those terms. For them it 

 is the natural, and not the supernatural, that has no existence. The 

 French officer of engineers who sinks through the gypsum crust of the 

 desert an artesian well, thus procuring for them the blessing of a new 

 date-grove, is, in their eyes, not a man of superior acquirement whose 

 eye penetrates to the interior of the earth, and who knows how to dis- 

 cover what there is hid, but a miracle-worker, who, albeit an infidel, is 

 on better terms with Allah than themselves, and who, like Moses of old, 

 strikes water from the rock. 



In that stage of human progress science does not as yet exist. It 

 is the childhood period of our race, and as such it has many points of 

 resemblance to the childhood of the individual man. As this is par ex- 

 cellence the period of unconscious inferences, so it is to be admitted that 

 such inferences, guided by experiment, have led to the invention of the 

 first tools. These were invented, not by one man, nor at one spot upon 

 the earth, but by many, and at points very distant from one another. 

 Thus originated levers, rollers, wedges, and axes ; clubs and spears ; 

 slings, sarbacands, lassos ; bows and arrows ; oars, sails, and rudders ; 

 fishing nets, lines, and hooks ; finally, the use of fire, by which, as by 

 speech, man is best distinguished from animals, and which even ana- 

 tomically stamps him with the character of a soot-stained lung. Man, 

 therefore, at an early period was un questionably entitled to the epithet 

 bestowed upon him by Benjamin Franklin of " the tool-making animal." 



II. The Anthropomorphic Age. 



Now, whatever confronted him in the shape of a compelling power 

 of Nature, being either beyond or adverse to his own will, and whether 

 the same affected him favorably or unfavorably, in it, owing to a pro- 

 pensity deeply rooted in the human mind, he recognized the act of 



