MICHIGAN ACADEMY OF SCIENCE. 91 



tion which we are accustomed to refer to as the "Dark Ages." Out of 



the darkness of tliese centuries of intellectual stagnation we catch a 



glimpse which indicates that individual minds were still active in their 

 search for the truth. 



It is the twentieth (hiy of .luiic in liit- year i:5»'0. The bells of W-ntiia are 

 ringinji in tlie bright Sabbath morning and the crowd is sahiting with respect a 

 tall and serious figure — the great Dante — who with slightly bowed head is enter- 

 ing the cliupcl of Santa Helena. Dante has today invited the whole educated 

 world of Verona to assemble in this ehapcl and listen to his discourse entitled 

 -De arqua et terra." He proposes to discuss the relative position of land and sea, 

 and as he tells us himself, every one came at his bidding, "with the exception of 

 a few, who feared by their presence to eonfinn the exceptional importance of 

 others." . . . 



With a gift for picture-writing never before equaled he has led his astoimded 

 contemporaries up to the abode of the saints and down into the depths of the 

 lower world. Now today he is returning to the starting-point of his most power- 

 ful creation, to the critical examination of that which is greater than all tlie 

 (•()ncei)tions of poetry — the actual ordering of the universe. 



Dante argued cogently for the spherical form of both the earth and 

 the seas, and in accounting for the elevation of the land areas above the 

 oceans, he even offered an early hint of the law of gravitation. The 

 earth, he argued, can not elevate itself; nor can the cause be water, fire 

 or air. He therefore suggested that the fixed stars might exercise this 

 influence "after the manner of magnets." 



The new era which ojiened with the revival of learning after a thou- 

 sand years of stagnation, was one dominated by new consideTations within 

 the realm of thought. Tlie keynote of the period was the dominating 

 inriuence of the Christian church, and for centuries all thinkers Avere 

 required to make their expressions conform to the dogmas of the church 

 of Rome. The emancipation supposed to have arrived with the Protestant 

 Reformation was a partial one only, and complete freedom of thought 

 was not secured until the modern period of science was ushered in in the 

 latter half of the nineteenth century. 



Living as we do when few obstacles are opposed to a full and free 

 expression, it will be profitable to review by means of examples the 

 position of science in the sixteenth and seventeenth centuries. In declar- 

 ing his belief in the heliocentric theory of the planets which Copernicus 

 had promulgated. Galileo in 1597 wrote cautiously to Kepler: 



It exi)Iains to me the cause of many j)hcn()mcna which according to the gen- 

 erally ac<'eptcd view are entirel}' incomjjrehcnsible. I have assembled many argu- 

 ments for combatting the latter, but I do not dare to bring them into the light 

 of puI)lication. T would certainly risk it if there were more men lik<- you. 



With the telescope M'hich he invented Galileo nightly studied the 

 hca\ens from his little tower in the outskirts of Florence, and to his 



