69 



suit of experiment, carried on extensively for years. 

 It was confined to the realm of natural cause and 

 effect, and therefore scientifically legitimate. 



There is a metaphysics of science, in the sense, that 

 many things, like the nature of the atom, or composi- 

 tion of matter, or of the medium called ether, are 

 speculative. But these are simply assumptions of the 

 unknown probabilities of matter and motion, based on 

 known phenomena. There is a very important distinc- 

 tion between natural and supernatural metaphysics. 

 An extreme, and the newest form of natural meta- 

 physics is a statement by Lodge, "What electricity 

 itself is we do not know, but it may perhaps be a form 

 of, or aspect of matter. Now we can go one step fur- 

 ther, and say that matter is composed of electricity, 

 and of nothing else." The use of metaphysics in the 

 ordinary meaning of the term, is confined to specula- 

 tions in the realm of the ' ' Unknowable Absolute, ' ' where 

 no experiment can be made. 



MALTHUS. Darwin was impressed with the theory 

 of Malthus. This is, that human life increases in 

 geometric ratio, while the means of subsistence mul- 

 tiply only in an arithmetical ratio. It is a curious 

 coincidence that Wallace should have independently 

 concluded, as Darwin did, that natural selection of 

 variations is the method of evolution, in the organfc 

 kingdom, but still more curious, that both should have 

 been pointed to the conclusion by the reading of 

 Malthus' "Principle of Population." 



The theory of Malthus would seem to apply more 

 truly to animals in the wild state than to man, because 

 they have no way of artificially increasing their food 

 supply, and adopt no methods of their own to restrict, 

 or increase, reproduction. 



