Larry Kramer's play, a semi-autobiographical, socially significant drama which became a hit in 1985, tracked the early years of the AIDS crisis through prickly activist Ned Weeks, a character based on the playwright himself. Though Ned is given a boyfriend in the play, his closest relationship is with his older brother, a powerful lawyer named Ben Weeks, who gives Ned legal advice. The two brothers break, however, in a powerful scene in which Ned challenged Ben to completely accept him as a gay man.

Playwright Kramer had much material to draw on in depicting the complicated relationship. Arthur, nine years older than Larry, basically raised his brother. But when, while in college, Larry confessed his homosexuality to his brother, Arthur hired a psychiatrist to cure him. In the 1980's, wrote the Times, Larry asked his brother to take on Gay Men's Health Crisis, the nonprofit organization he helped found, as a client. Arthur dodged the issue and when Larry managed to get another partner at the firm to take GMHC on, a rift grew between the siblings. Another time, Larry threatened to call a gay boycott of MCI, which had been accused of discrimination against a former employee who was gay. MCI just happened to be one of the Kramer firm's biggest clients.

Arthur Kramer gradated from Yale University in 1953. When he discovered that it was difficult for a Jew to get a job in the well-established firms, he and two friends, Maurice Nessen and Foster Bam, founded a law firm of their own in the early 1960s, according to The New York Times. It became what is now Kramer Levin Naftalis & Frankel, a firm that has more than 300 lawyers and offices in Paris and New York.

The two brothers' relationship softened in later years. Mr. Kramer's relationship with his brother caused him to become an advocate for various gay causes. In 2001, Mr. Kramer gave Yale University a $1 million grant to create the Larry Kramer Initiative for Lesbian and Gay Studies. And his law firm has played a role in marriage rights for gay couples.

A story about the brothers' ultimate reconciliation appeared on the front page of The New York Times in 2006. "For Arthur, the reconciliation came as he accepted that his brother was not going to change, and that being gay was a matter of biology, not choice or family dysfunction," the article read. "'I was persuaded over time that there was nothing you could do about it, and it was my problem.'" He is survived by his brother, of Manhattan; his wife, Alice; their children, Liza, of Berkeley, Calif.; Rebecca, of Manhattan; and Andrew, of Sands Point, N.Y.; another daughter, Andrea McNicol, of Manhattan; and four grandchildren.