Daniel Aaron, the literary scholar, has died.

Though Aaron was one of the last of the greats who made American midcentury letters what it was, I only truly came to his work (after dipping in and out of it for years) recently. This past summer, in fact. I was preparing for my talk on public intellectuals, so I read Writers on the Left. I thought I knew the broad outlines of American writers and the left in the first half of the twentieth century. Ten pages into the book, I realized I didn’t know anything.

I remember long rides on the subway, from Coney to Forest Hills and back, taking notes on the back pages of the book. I felt like I was in a race against time: the pages were crumbling apart, as was the binding, and all I could do was write faster and more sparingly, hoping the book wouldn’t come undone by my marginalia.

I also remember feverishly texting friends—with my primitive phone, that’s all I could do on the subway—about some nugget I found in Aaron’s book: a tidbit for Jason Frank about Whitman being the most translated American writer of the Russian Revolution (am I misremembering this?), another tidbit on the Patterson silk workers’ strike for Alex Gourevitch, text after text about the bloody crossroads of literature and politics.

There are fastidious works of scholarship, and there are intellectual adventures. Aaron’s book was both.