7] Introduction. 199 



Oftentimes when a little investigation of facts would lead 

 to a correct conclusion, men waste their time in a weari- 

 some discussion of hypotheses, or a juggling of words and 

 highsounding phrases, and content themselves with con- 

 clusions which can only claim to be plausible guesses. 



Sects and parties are made most readily upon the 

 subjects of which men are the most ignorant, and if any- 

 one is sufficiently honest to Confess his ignorance, he is 

 branded as disloyal. 



Science would teach men to practice common honesty 

 in forming their conclusions. It would lead their minds to 

 always hold open court, ready to receive further evidence. 



People have great difficulty in drawing honest conclu- 

 sions because they have so many preconceived notions. 

 They perform experiments for the purpose of corroborat- 

 ing their ideas rather than for the purpose of gaining new 

 ideas or correcting old ones; and, with careless habits of 

 experimenting and careless habits of observing, it happens 

 that their inferences are illogical and imaginary. In this 

 way people deceive themselves until they believe what- 

 ever accords with their philosophy and reject all evidence 

 to the contrary, though it be the unmistakable evidence 

 of their own senses. Caesar, in his commentaries of the 

 Gallic Wars, remarks that "men believe most readily those 

 things which they wish to," and the old proverb runs 

 "A man convinced against his will is of the same opinion 

 still." If a man can will to believe what he is convinced 

 is not true, what inconsistency! The citizen needs a train- 

 ing in natural science that he may be cured of his whims. 

 Lastly he needs this training that he may be freed from 

 the bondage of over-credulity. 



III. CRITICISMS UPON SOME OF THE PRESENT METHODS OF 

 TEACHING NATURAL SCIENCE. 



In geometry we demonstrate the first proposition before 

 we try to understand the second, and so on, step by step, 



