954 



SCIENCE 



[N. S. Vol. XXXIII. No. 860 



The world little knows how many of the 

 thoughts and theories which have passed through 

 the mind of the scientific investigator, have been 

 crushed in silence and secrecy by his own severe 

 criticism and adverse examination; that in the 

 most successful instances, not a tenth of the sug- 

 gestions, the hopes, the wishes, the preliminary 

 conclusions have been realized. 



It is a matter of common observation 

 that men who have done most to widen the 

 boundaries of human Imowledge, are the 

 ones who are most frequently in a state 

 of doubt. They are always ready to take 

 the whole matter into consideration again 

 when some preliminary conclusion is con- 

 fronted with conflicting evidence. In 

 physics where we seek the relation between 

 various values which are simultaneously 

 involved in some function, as in the bend- 

 ing of a beam under a load, we can vary 

 one quantity only, and find its effect on 

 the result. When this has been done with 

 all of the variables which are concerned, 

 the entire equation involving the simul- 

 taneous effect of all the variables can be 

 written. When we undertake to determine 

 the effect upon a nation, of some national 

 policy, we are never able to control condi- 

 tions in two successive experiments. We 

 can not eliminate the disturbing effect of 

 other influences or conditions which have 

 also changed and which are of importance 

 in determining the result. But the polit- 

 ical orator is never in doubt. He speaks 

 with as much of assurance as a lawyer, 

 who argues a case in court. 



It is not the duty of a scientific man to 

 defend what is generally believed to be the 

 truth. The mental attitude of the advo- 

 cate is foreign to every instinct that the 

 man of science should possess. In Gali- 

 leo's time we can well understand how the 

 man of science should actively contend in 

 quarrelsome debate with those who refused 

 to look through his telescope. It was 

 enough for them to know that there were 



seven openings in the head, seven metals, 

 and seven days in the week. This was 

 proof enough that there could only be 

 seven planetary bodies. The moon and the 

 sun were perfect as they came from the 

 hand of the creator. This was proof 

 enough that there could be no mountains 

 and valleys on the moon, and no spots on 

 the sun. It needs no telescope to settle 

 such questions. That all bodies do not fall 

 with the same acceleration has been al- 

 ready passed upon in a prior decision. It 

 is sufficient to cite that opinion, and Gali- 

 leo's experiment at the tower of Pisa 

 counts for nothing. 



Galileo was himself a product of an age 

 characterized by ideas of this kind. In his 

 day his mental attitude was perhaps need- 

 ful. There are times when the soil must 

 be plowed. In our time the man of science 

 is free to go his own way in the pursuit of 

 his work and in publishing it to the world. 

 If one feels dissatisfied with the present, 

 he can do nothing better than to read 

 history. 



I have often felt that scientific students 

 of our time would be greatly benefited by 

 reading much more of history than is their 

 custom. There are some most interesting 

 remnants of scientific history, connected 

 with the Moorish occupation of Spain. 

 The work of Alhazen, who lived about 

 1100 A.D. would have been creditable in 

 any age. It requires great patience for 

 one living in this age to read European 

 history during the times of Luther and 

 Galileo. It is, however, only in this way 

 that we can realize what progress the 

 world has been making. 



It is, however, a satisfaction to know 

 that nations have never been driven to 

 bloody wars in order to enforce the doc- 

 trine of universal gravitation, or Kepler's 

 third law, or the doctrine of evolution. 



We do learn that in those earlier times. 



