SCIENCE AND SOCIAL PROCRESS 241 



from tradition. This is a different thing from what is commonly under- 

 stood by freedom of thought. Under certain conditions men seem inca- 

 pable of thinking outside of traditional ways, while under other condi- 

 tions they may show great mental vigor in the face of severe persecution. 

 As rigidly prescribed beliefs in society are usually due to the authority 

 of religion, emancipation from theological restrictions must usually 

 precede periods of mental activity. History gives us two well-marked 

 periods of scientific advance, the Greek period of scientific thought 

 and the modern period beginning in the sixteenth century, and 

 both movements began under similar circumstances. In both 

 cases emancipation from theological dogmas preceded scientific 

 activity, and this emancipation was accomplished by the stimu- 

 lating effects of geographical discoveries. In Greece some of the old 

 religious myths were actually disproved by these discoveries, while 

 belief in others was undermined by the enlarged ideas resulting from 

 them. Similarly in modern times the intellectual life was greatly 

 stimulated by the discovery of America and the circumnavigation of the 

 globe; and the authority of the church was weakened by its strong 

 opposition to the Copernican system. In 1616 the Inquisition issued 

 an edict, which has never been repealed, declaring that to suppose the 

 sun the center of the solar system was false and contrary to the 

 Scriptures. 5 In the modern period of enlightenment, it is true that 

 society was by no means stagnant when the discoveries were made; in 

 fact, the discoveries themselves were due to an awakening intellect which 

 may be traced to several sources, the chief of which is doubtless the 

 travel and trade resulting from the crusades. Traced back to their 

 source, therefore, it will be seen that the religious superstitions were 

 themselves responsible for the movement which finally exterminated 

 them. If the intellectual development of the Arabians is considered 

 to be a third period of scientific growth, we shall find that that also was 

 preceded by extended migrations and conquests, which affected greatly 

 the active religious beliefs of the Mohammedan conquerors. The whole 

 intellectual attitude of the Saracens changed after their conquest of 

 Africa. Although in the three cases just cited geographical discoveries 

 were responsible for the change in the mental attitude, no one event 

 can be held responsible in all cases for the emancipation of the mind. 

 If the forces of conservatism are very strong, a powerful social upheaval 

 may be necessary to prepare the way for the reception of new truths. 

 If, however, the intellectual condition is less rigidly fixed, milder influ- 

 ences may serve to stimulate thought. After scientific development has 

 once begun, the succession of new truths themselves is the best guaran- 

 tee against the excessive influences of tradition. 



Ordinarily an active society will free itself from the bonds of tradi- 



5 ' ' The Cambridge Modern History, ' ' Vol. V., p. 714. 



VOL. LXXIX. — 17. 



