SOURCE: Introduction to The Galileo Affair: A Documentary History, edited and translated by Maurice A. Finocchiaro, University of California Press, 1989, pp. 1-46.

In the following excerpt, Finocchiaro describes Galileo 's personality as it clashed with the tenor of the times, and explains Copernicus 's heliocentric theory as well as its limitations, showing how, thanks to his improvements on the recently invented telescope, Galileo was able to eliminate most of those limitations.

Nonintellectual Factors

Beginning with personal or psychological factors, it is easy to see that Galileo had a penchant for controversy, was a master of wit and sarcasm, and wrote with unsurpassable eloquence. Interacting with each other and with his scientific and philosophical virtues, these qualities resulted in his making many enemies and getting involved in many other bitter disputes besides the main one that concerns us here. Typically these disputes involved questions of priority of invention or...