12 Mr. M. M. P. Muir on Chemical Notation. 



the atomic (and therefore, it appears to me, against the 

 molecular) theory of matter is, that this theory is not a 

 result of inductive reasoning. An objection, in principle the 

 same, is stated in his paper already referred to (Phil. Mag. 

 Jan. 1876*), in these words (he is speaking of the examination 

 of natural phenomena) : — " Instead of demanding a theory, it 

 would be better to ask how we could dispense with one. It 

 is juster and wiser to adhere to facts than attempt to transcend 

 them." 



In making such statements as these, it appears to me that 

 Dr. Mills has misapprehended the method by which science 

 gains her finest results. That method, I would make bold to 

 say, is not entirely an inductive one ; it makes use likewise of 

 deductive reasoning. Science begins with facts ; by observa- 

 tion and experiments she accumulates facts ; by a proper use 

 of imagination she frames hypotheses to account for the facts; 

 and by subsequent appeal to facts she proves or disproves the 

 truth of her hypotheses. Had science dealt with facts by 

 strictly inductive methods only, she would never have been 

 able to rise to those general expressions which we call laws. 

 Hypotheses must be framed if science is to make any advances. 

 Given a large number of facts, it might be possible, by ar- 

 ranging these in all possible combinations, to arrive at last at 

 a proper classification ; but this method is utterly impracti- 

 cable, because of the vast number of data to be dealt with. It 

 may be affirmed with a considerable amount of certainty that 

 every great advance in science has been made by the use of 

 hypotheses. Newton professed not to deal with hypotheses ; 

 but what is the ' Principia ' but the record of wonderful dis- 

 coveries which became possible only by the greatest freedom 

 in theorizing? Kepler theorized; Hooke asserted that the 

 natural philosopher must be ready to guess the solution of 

 many phenomena ; Sir Humphry Davy did not despise hy- 

 potheses ; and who made freer use of his imagination than 

 Faraday? — the greatest of all experimental philosophers. In 

 framing hypotheses we must see that they agree with facts ; 

 in other respects they may be as inconceivable (not self-con- 

 tradictory) as any fairy tale. The suppositions involved in 

 the theory of gravitation, and in the undulatory theory of 

 light are seemingly sufficiently absurd ; in the latter theory 

 we are compelled to imagine the existence throughout space 

 of a so-called aether, possessed of the highest elasticity, and at 

 the same time more solid than steel ! Dr. Thomas Young even 

 imagined (and it would appear that we cannot deny the possi- 

 bility of his imaginings being true) " that there may be in- 

 dependent worlds .... pervading each other, unseen and un- 



