NEW YORK — Few minds were as playful and as serious as E.L. Doctorow’s.

Conjurer of old-time gangsters and ragtime stars. Commentator on wars and presidents and the laws of the land. Student of political and literary history and how they tell us who we are now.

Doctorow, who died Tuesday at age 84, was the rare American writer to move gracefully between lives as engaged citizen and solitary inventor.

“Underlying everything — the evocative flashes, the dogged working of language — is the writer’s belief in the story as a system of knowledge,” he wrote in the introduction to his essay collection “Creationists,” published in 2006. “This belief is akin to the scientist’s faith in the scientific method as a way to truth.”