512 EDUCATION 



habit of open-mindedness to new ideas. Only biologists are in a 

 position to know the fundamental facts to ascertain what is 

 "inborn" and what "acquired" in the human mind, and to 

 discover how any desired quality may best be evolved or 

 developed, and any defect eliminated. When we think about 

 what is good or bad in education, we think in terms of causation. 

 Not until biologists have trained their students by direct methods 

 to become skilful in the interpretation of evidence, and thus have 

 raised a body of workers capable of becoming effective thinkers 

 about education, not until their science teaching has become 

 scientific in method, will they be in a postion to speak with the 

 authority that is their right. And not until then will the mental 

 training of the general public receive a reform of which there 

 is urgent need, and the practical utility and intellectual splendour 

 of biology be recognized by all men. 



835. In this book, now finished, I have tried, however un- 

 successfully, to follow the only method by which all thinkers 

 who have expressed themselves on the subject have supposed it 

 possible to trace sequences of cause and effect with any degree 

 of certainty the method of using some (as many as possible) 

 of the available, authentic, and relevant facts for the foundations 

 of hypotheses, and the remainder (which of necessity are usually 

 by far the greater number) to test the correctness of the thinking 

 the method of fitting each inference to all the facts, no matter 

 how numerous or how gathered, and so of never resting content 

 until every devisable test had been satisfied. "An hypothesis 

 is any supposition which we make (either without evidence, or on 

 evidence avowedly insufficient) in order to endeavour to deduce from 

 it conclusions in accordance with facts which are known to be real ; 

 under the idea that if the conclusions to which the hypothesis 

 leads are known truths, the hypothesis itself must be, or at least 

 is likely to be, true." l The reader has perhaps noted that, while I 

 have rarely, if ever, contradicted alleged facts, many of which in 

 common with all other people I have been obliged to accept at 

 second hand on what appeared good authority, I have often con- 

 troverted inferences, none of which we are obliged to accept at 

 second hand, which seemed to me, when tested, to conflict with 

 well-known and undisputed truths. " An opinion which stands in 

 need 'of much illustration can often receive it most effectually, 

 and least tediously, in the form of a defence against objections. 

 And on subjects concerning which speculative minds are still 

 1 J. S. Mill, Logic, iii. xiv. 4. 



