It was the big tech equivalent of “drink responsibly” or the gambling industry’s “safer play”; the latest milestone in Silicon Valley’s year of apology. Earlier this month, Facebook and Instagram announced new tools for users to set time limits on their platforms, and a dashboard to monitor one’s daily use, following Google’s introduction of Digital Well Being features.

In doing so the companies seemed to suggest that spending time on the internet is not a desirable, healthy habit, but a pleasurable vice: one that if left uncontrolled may slip into unappealing addiction.

Having secured our attention more completely than ever dreamed, they now are carefully admitting it’s time to give some of it back, so we can meet our children’s eyes unfiltered by Clarendon or Lark; go see a movie in a theater; or contra Apple’s ad for its watch, even go surfing without — heaven forfend — “checking in.”

“The liberation of human attention may be the defining moral and political struggle of our time,” writes James Williams, a technologist turned philosopher and the author of a new book, “Stand Out of Our Light.”