From the Wikipedia:
"Born in Boston, Quigley attended Harvard University, where he studied history and earned B.A, M.A., and Ph.D. degrees. He taught at Princeton University, and then at Harvard, and then from 1941 to 1976 at the School of Foreign Service at Georgetown University.
From 1941 until 1972, he taught a two-semester course at Georgetown on the development of civilizations. According to his obituary in The Washington Star, many alumni of Georgetown's School of Foreign Service asserted that this was "the most influential course in their undergraduate careers".
In addition to his academic work, Quigley served as a consultant to the U.S. Department of Defense, the United States Navy, the Smithsonian Institution, and the House Select Committee on Astronautics and Space Exploration in the 1950s. He was also a book reviewer for The Washington Star, and a contributor and editorial board member of Current History.
Quigley retired from Georgetown in June 1976 after being honored by the student body with its Faculty Award for the fourth consecutive year. He died the following year at Georgetown University Hospital following a heart attack."
From the Wikipedia:
"Quigley's work emphasized inclusive diversity as a core value of Western civilization, contrasting it with the dualism of Plato. He concluded the book Tragedy and Hope with the hope that the West could "resume its development along its old patterns of Inclusive Diversity". From his study of history, "it is clear that the West believes in diversity rather than in uniformity, in pluralism rather than in monism or dualism, in inclusion rather than exclusion, in liberty rather than in authority, in truth rather than in power, in conversion rather than in annihilation, in the individual rather than in the organization, in reconciliation rather than in triumph, in heterogeneity rather than in homogeneity, in relativisms rather than in absolutes, and in approximations rather than in final answers."
Quigley asserts that any intolerance or rigidity in the religious practices of the West are aberrations from its nature of inclusivity and diversity. Quigley points to the tolerance and flexibility in Aquinas's belief that theological truth is revealed over time through dialogue within the Christian community, which allows the community to adapt to a changing world.
Institutionalization and the fall of civilizations
Having studied the rise and fall of civilizations, "Quigley found the explanation of disintegration in the gradual transformation of social 'instruments' into 'institutions,' that is, transformation of social arrangements functioning to meet real social needs into social institutions serving their own purposes regardless of real social needs".
Weapons and democracy
From a historical study of weapons and political dynamics, Quigley concludes that the characteristics of weapons are the main predictor of democracy. Democracy tends to emerge only when the best weapons available are easy for individuals to buy and use. This explains why democracy occurs so rarely in human history.
In the 1800s (peaking in the 1880s), guns were the best weapon available. In America, almost everyone could afford to buy a gun, and could learn how to use it fairly easily. Governments couldn't do any better: it became the age of mass armies of citizen soldiers with guns. (Similarly, Periclean Greece was an age of the citizen soldier and of democracy).
In the 1900s, expensive, specialist weapons (such as tanks and bombers) became available, and citizen soldiers became dominated by specialist soldiers. Quigley notes that the slaughter of World War I (1914-1918) was due to the mismatch between the traditional armies (citizen soldiers) and the available weapons (machine guns used defensively)."
- The Evolution of Civilizations: An Introduction to Historical Analysis (1st ed.). New York: Macmillan Publishing Company. 1961. Hardcover. 281 pages