i The. Study of Nature 9 



1 6. Cause and Effect. The relation of Cause and Effect 

 is the fundamental law of Nature. There is no recorded 

 instance of an effect appearing without a previous cause, or 

 of a cause acting without producing its full effect. Every 

 change in Nature is the effect of some previous change and 

 the cause of some change to follow ; just as the movement 

 of each carriage near the middle of a long train is a result 

 of the movement of the one in front and a precursor of the 

 movement of the one behind. Facts or effects are to be 

 seen everywhere, but causes have usually to be sought for. 

 It is the function of science or organised knowledge to 

 observe all effects, or phenomena, and to seek for their 

 causes. This twofold purpose gives richness and dignity 

 to science. The observation and classifying of facts soon 

 becomes wearisome to all but the specialist actually engaged 

 in the work. But when reasons are assigned, and classifi- 

 cation explained, when the number of causes is reduced 

 and the effects begin to crystallise into essential and clearly 

 related parts of one whole, every intelligent student finds 

 interest, and many, more fortunate, even fascination in the 

 study. 



17- Inductive and Deductive Reasoning. Reason 

 may be applied to the study of facts in two different ways. 

 Inductive Reasoning is the arduous process of finding the 

 meaning of phenomena by collecting and classifying facts 

 and thinking out their causes. Deductive Reasoning is the 

 shorter operation of finding what effects must result from 

 the operation of a known cause. It is often supposed that 

 since we can observe facts alone the inductive method of 

 reasoning is the only one which can be employed in study- 

 ing Nature, but the number of facts even in one small 

 department is so great that life is not long enough for the 

 labour of collecting, classing, and discussing them all. 



1 8. The Scientific Method of discovering the causes of 

 phenomena involves the use of both inductive and deductive 

 reasoning linked together by imagination, a mental power 

 which is as essential to the scientific discoverer as it is to 

 the poet. After observing a considerable number of facts 

 the investigator imagines a possible cause or explanation, 



