Well, not really ancient, but this is what I've read recently:
Samuel Huntington's The Clash of Civilizations and the Remaking of World Order
West is declining, Islam and China are increasing
2 major parts of a civilization = religion and language (both different between West and Islam)
US, Europe = Western = Davos culture = value individualism, market economy, speak English, democracy, separate religion and government, loyalty to nation (vs tribes &/or religion)
Islam view = superior culture, inferior power
West view = superior culture, superior (but declining) power
Islam & Christianity = monotheistic (don't assimilate other religions well), see world as dualistic (us vs them), teleological, universalistic (we're right, they're wrong), obligation to convert nonbelievers (jihads and crusades)
westernization != modernization (can modernize without becoming western)
Bernard Lewis' What Went Wrong? : The Clash Between Islam and Modernity in the Middle East
West succeeded, Islam failed
religion and politics closer in Islam
Islam was aloof from past successes -> inward looking -> failure to adapt successful practices of other countries -> failure to modernize
westernization = modernization, Islam rejects westernization & therefore modernization
Muslims must stop blaming external events/actors for their problems and focus on fixing them instead
Richard Bulliet's The Case for Islamo-Christian Civilization
both Huntington and Lewis are wrong; Islam and Christianity can get along
Islam not inherently church + state, anti-democracy, etc and will become more Western
all of the current problems between Islam and Christianity were present between Judaism, Catholicism, and Protestantism in the past and were resolved; they will be resolved between Islam and Christianity, too