6 DOCTRINE OF EVOLUTION 



something that is somehow apart from daily life and 

 antagonistic to freedom of thought. But this is far 

 from being true. Karl Pearson defines science as 

 organized knowledge, and Huxley calls it organized 

 common sense. These definitions mean the same thing. 

 They mean that in order to know anything that de- 

 serves confidence, in order to obtain a real result, it 

 is necessary in the first place to establish the reality 

 of facts and to discriminate between the true, the not 

 so sure, the merely possible, and the false. Having 

 accurate and verified data, scientific method then 

 proceeds to classify them, and this is the organizing 

 of knowledge. The final process involves a summary 

 of the facts and their relations by some simple ex- 

 pression or formula. A good illustration of a scientific 

 principle is the natural law of gravitation. It states 

 simply that two bodies of matter attract one another 

 directly in proportion to their mass, and inversely in 

 proportion to the square of the distance between them. 

 In this concise rule are described the relations which 

 have been actually determined for masses of varying 

 sizes and at different distances apart, for snowflakes 

 falling to the earth, for the avalanche on the mountain 

 slope, and for the planets of the solar system, moving 

 in celestial coordination. 



Such a principle as the law of gravitation, like evolu- 

 tion, is true if the basic facts are true, if they are reason- 

 ably related, and if the conclusion is drawn reasonably 

 from them. It is true for all persons who possess 

 normal minds, and this is why Huxley speaks of science 

 as " common sense," that is, something which is a 

 reasonable and sensible part of the mental make-up of 



