He was a colleague of Thornton Wilder, who mentored him, and an admirer of the work of Frank Capra. Kanin said "I'd rather be Capra than God, if there is a Capra." Kanin and Katharine Hepburn were the only witnesses to Laurence Olivier and Vivien Leigh's wedding in California on August 31, 1940. In 1941, he and Katharine Hepburn worked with his brother Michael Kanin and Ring Lardner, Jr., on the early drafts of what would become Woman of the Year right before Garson enlisted in the army. He is also quoted as saying, "When your work speaks for itself, don't interrupt."