For the first meeting of his book club for men, Yahdon Israel, a 35-year-old senior editor at Simon & Schuster, asked the participants to bring a favorite work of fiction. Not everyone completed the assignment.

One man brought “Watchmen,” a graphic novel. Valid, technically.

Another scoured his home bookshelf and realized he did not own a single novel or short story collection. So he showed up to the meeting with a nonfiction book about emotional intelligence. (Mr. Israel posted a photo of the seven millenial-ish men in the group, each holding his selection, to his Instagram account.)

Mr. Israel, who has hosted another book club for nearly a decade, started this group last December in an effort to inspire heterosexual men to read more fiction. He solicited members over social media. For the second meeting, he assigned a story collection by Jamel Brinkley, “A Lucky Man,” which examines contemporary masculinity. For two hours, the men discussed the book, and the theme.

The next day, Mr. Israel had a panic attack. Two days later, he said, he was diagnosed with depression.

He has spent the months since grappling with painful realizations that came out of the discussion, about how toxic masculinity has harmed his own marriage, especially the idea that real men do not share their feelings. It was an epiphany out of James Joyce, unlocked, he said, by that conversation in the book club.

Indeed, while Mr. Israel might have convened the group to help other men read more fiction, he has since realized that there’s an even deeper reason.