Ladies and Gentlemen: For eight abbreviated hours I am to endeavor to occupy your attention with the subject of reasoning. But can one person inform another what is good reasoning and what is bad? About seventy generations have passed since Aristotle gave to logic a scientific form. There has not been one of those generations in Europe that has not been occupied with this study and it is natural and proper to ask what the harvest has been. At the end of sixty of those seventy generations, Europeans reasoned no better than the personages of Plato's Dialogues are represented as reason ing. They were more considerably more adroit - they reached their conclusions with greater facility, but the conculsions
were neither more sure nor further-reaching; and as to the character of the reasoning, it was of a decidedly less vigorous and fecund [beind?] them than of Plato himself. As for the science of logic, if remained substantially the very doctrine that Aristotle had taught.
Galileo inaugurated the science of dynamics about 1590, and his work was well-known and had its effect, although his book was not published for near half a century later; and it was the study of dynamics, more than anything else, which gradually taught men to reason better on all subjects. I do not say that it was the sole cause; for [Taycho-Brohe?] established his observatory half a dozen years before Galilego was appointer professor in Pisa; and the [gorincepto?] of our system of