The majority of the catholic clergy preached peace and compassion, but you didn't need a majority to propagate the crusades. In fact, it is precisely because of how the majority maintains credibility and goodwill with the public that they can utilise bad actors who claim to represent their interests.
Moreover, I didn't invent the word scientism. It refers to a specific subset of politics. Sam Harris and Richard Dawkins are both good examples of people who preach crusades in the name of scientism, promising that this time, we're plundering Jerusalem in the name of logic and reason.
There's a wonderful debate between Hitchens and Parenti that shows this phenomenon:
