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Louis Agassiz. 



Let me illustrate the effect of the introduction of 

 great ideas into science. I will select one example 

 from astronomy, and one from geology. 



Before the time of Copernicus and Galileo, this, 

 our earth, was all of space for us. Sun, moon, and 

 stars were but little satellites revolving about us at 

 inconsiderable distance. Astronomy then was but 

 the geometry of the heavens, the geometry of the 

 curious lines traced by these wandering fires on the 

 concave board of heaven. But with the first glance 

 through the telescope, the phases of Venus and the 

 satellites of Jupiter revealed the existence of other 

 worlds beside our own. In that moment the funda- 

 mental idea of modern astronomy, the idea of infinite 

 space filled with worlds like our own, was fully born 

 in the mind of Galileo. In that moment the intel- 

 lectual vision of man was infinitely extended. 



Again, before the time of Buffon and Cuvier, this, 

 our human epoch, the history of our race, was all of 

 time for us. Shells and other remains of marine 

 animals had, indeed, been found far in the interior of 

 the continents, and high up the slopes of mountains, 

 and there had been much speculation as to the 

 origin of these. Some may have thought by means 

 of these to extend the limits of our epoch, but none 

 dreamed of other epochs. Some may have thought 

 they were discovering new coast islands along the 

 shores of time ; but none dreamed that these were 

 the evidences of new worlds in the infinite abyss of 

 time. It was reserved for Buffon and Cuvier first to 

 recognise the entire difference between fossil and 

 living species, In that moment was born the funda- 



