Earlier this week, Harper’s Magazine published an attention-getting open letter—signed by more than 150 prominent, mostly left-of-center writers, academics, artists, and activists—basically calling for the free and vigorous expression of ideas, asking for courteous and respectful debate about them, and lamenting quite-excessive reactions against dissenters from reigning orthodoxies.

Attention-getting, and controversy-causing. While one wouldn’t normally think these positions too contentious, actually, they apparently are so in certain quarters—at least if judging by some of the online commentariat’s overheated, decidedly non-courteous reaction to the letter and some of those who signed it. It’s often the reactions like these to such actions that are most telling; here, too.

The whole letter is worth the inspiring read, maybe even a quick tweet. While not citing specific incidents, it references a need for open debate and toleration in several contexts—importantly, including philanthropy.

“Our cultural institutions are facing a moment of trial,” it begins.

Powerful protests for racial and social justice are leading to overdue demands for police reform, along with wider calls for greater equality and inclusion across our society, not least in higher education, journalism, philanthropy, and the arts. But this needed reckoning has also intensified a new set of moral attitudes and political commitments that tend to weaken our norms of open debate and toleration of differences in favor of ideological conformity. As we applaud the first development, we also raise our voices against the second.

Such voices sure should be raised, and heard—including in philanthropy, where a heavy-handed groupthink may be taking particular, and particularly harmful, hold. Harper’s should be admired for organizing the letter. So too its liberal signers, whether they knew it’d be considered an act of courage or not.