Recently the FBI director Christopher Wray said that he has focused on stopping violence rather than ideology: you can think anything you want, but being violent is what will trigger the Feds’ attention. His statement may sound odd, if like me you think that people who kill after writing ideological manifestos are largely motivated by, well, ideology.

But past experience with jihadism is instructive here. Jihadists believe many things that many ordinary peaceful Muslims believe; they take those beliefs and pursue them with extreme intellectualized violence. How do you police an ideology shared in part by millions of law-abiding citizens? Given that Americans are supposed to enjoy freedom of conscience, how do you police an ideology at all?

As we learn more about the perpetrator, we will doubtless discover that he said vile and alarming things, online and off, long before he started killing. In retrospect all these statements will feel like tragic missed opportunities to strait-jacket a young man and save both his life (he will soon face Texas justice, after all) and the lives of at least 20 others. But keep in mind how commonplace, on a sentence-by-sentence level, portions of that manifesto are. Just how many strait-jackets can our society afford?