256 MECHANICAL BASIS OF NATURAL SCIENCE. 



Professor Ray Lankester, speaking for " all schools of thinkers 

 who are acquainted with the facts," says, 



" The consensus is complete : Man is held to be a part of nature, a 

 product of the definite and orderly evolution which is universal ; a being 

 resulting from and driven by the one great nexus of mechanism which 

 we call Nature."* 



It is only fair, however, to say that in the next line the Professor 

 says (whether consistently or not) that 



" man stands alone, face to face with that mechanism. It is his destiny 

 to understand and to control it." 



An approach was made to the mechanical ideal when it was dis- 

 covered that heat and light were modes of motion. Another 

 approach to the same ideal has been made more recently by 

 discoveries connected with the corpuscular composition of the 

 atom. This discovery (or probable hypothesis) is stated by 

 Professor Duncan as follows : — 



" Our theory of the atom is that it is a sphere of positive electrification 

 enclosing a number of negatively electrified corpuscles. The corpuscles 

 are similar in all respects with the exception of mere velocity." 



It is the different modes in which the corpuscles are grouped 

 and the differences of the number of corpuscles in each group 

 that account for the atoms of the different elements. Working 

 from this theory 



" we have been able to explain all the mysteries of matter which it has- 

 been the function of the preceding pages so describe." 



He refers to the law of the periodicity of the atoms of the elements 

 their various valencies, and the phenomena of those elements 

 which are inert, i.e. which display no valency whatever. f 



II. Criticism of the Mechanical Theory. 



Science aims at simplification, and the mechanical theory of 

 science is an instance of such simplification. It is calculated, 

 as Mr. Balfour says, to excite in us " a feeling of acute intellectual 

 gratification." But the more a theory pleases us the more closely 

 it should be examined, and we turn to the criticisms with which 

 this theory has been assailed. 



I. In the first place, we have the criticisms of the so-called 

 " Descriptive School " of Scientists. 



It may be true, say the members of this school of thought, that 

 the mechanical theory gives us a true description of the sequence 

 of phenomena, but we must not think that it brings us any nearer, 

 as Professor Hicks' words assert, " to what goes on behind what 

 we can see or feel." 



" The object of Natural Science," says Prof. Whetham, " is to fit to- 

 gether a consistent and harmonious model which shall represent to our 

 minds the phenomena which act on our senses ; ... we cannot de- 

 cide whether that model .... represents truly the real structure 

 of Nature ; whether, indeed, there be any Nature as an ultimate reality 

 behind its phenomena." J 



* " Kingdom of Man," 1907. 



f The New Knowledge, pp. 171. 150. 



i " Recent Development of Physical Science," p. 14, 15. 



