Will Eisner, who died in January at the age of 86, was a genius. In a career that lasted 70 years, he played a role in the development of comics as a serious medium similar to that Louis Armstrong played in the development of jazz – he didn’t invent its grammar and vocabulary, but he refined and codified it, and he served as his form’s greatest ambassador.

His story is familiar. Born in Brooklyn in 1917 to European Jewish emigres, he began his career as a cartoonist at 19. Almost immediately he founded his own studio, where, among others, the inventors of Batman and the Fantastic Four were apprenticed to him. Eisner’s early fame came for his strip “The Spirit,” a newspaper supplement about a superhero with no superpowers. Its noirish tone, concern for social justice, and wildly energetic layouts were completely unlike anything anyone had seen before, seemingly having more in common with Orson Welles than with the Sunday funnies.

During World War II, Eisner worked as a cartoonist for the government; after it was over, he returned to a successful career as a freelancer, producing educational materials for the government while continuing his work on “The Spirit” and other strips. It was the work he began in his 60s, though, that would have the greatest influence.

In 1978 Eisner published “A Contract With God,” four interrelated stories about Jewish life in a Bronx tenement during the Depression. The book was remarkable for several reasons – the first comic by an American to be presented as a graphic novel, its loose, free layouts and expressive, unapologetically cartoonish line drawings had nothing whatever to do with the fervid, heroic fantasies comics were associated with at the time. Along with the tone of the stories – which recalled the Singers and Sholom Aleichmen rather than Superman – the presentation suggested entirely new directions for the form. Huge, borderless panels flowed seamlessly into one another and took advantage of empty space and the natural motion of the eye.

Eisner would go on to write and draw nearly two dozen more graphic novels over the next 30 years, the worst of them noteworthy and the best superb. Plain, straightforward, and forthrightly moral in tone, they dealt with everything from Vietnam to the Jewish experience in turn-of-the-century London. He adapted “Moby Dick” and published sketches of the people he encountered in New York. All along he stuck to what was closest to his heart – the Jewish experience in America, prejudice, justice, the anonymity and cruelty of city life, and the personal relationship between man and God.

Nor was this all. Eisner literally wrote the book on why and how comics function as a distinct aesthetic medium that can stand beside film as one of the great innovations of the 20th century. (The book is called “Comics and Sequential Art.”) He taught a course at the School of Visual Arts and patiently explained his life’s work to any reporter with a notebook. And he never stopped working.

“The Plot” (W.W. Norton, 142 pages, $23.95), on which Eisner worked right up until his death, is essential for his followers; for those unfamiliar with his work, it is an ideal introduction. Eisner boils down the Borgesian origins and destiny of the famed Protocols of the Elders of Zion, which purport to disclose the intentions and methods of a shadowy international Jewish conspiracy aimed at world domination, into a few thousand words and a bit of ink.

“The Plot” encompasses all his deepest concerns: history, persecution, the simple stupidity of man, the need for art that educates and serves a purpose beyond the expression of the artist’s intuitions and sensations. It also features some of his purest storytelling.

The Protocols had dual origins in agitations against Napoleon III and machinations against Russian Jewry in the court of Tsar Nicholas II. With characteristic economy Eisner disposes of this complicated background in a few pages and gets right to the heart of things: the 1898 forgery of the Protocols by a Russian spy named Golovinski, their 1905 publication, their wide dissemination, the 1921 expose by the Times of London that conclusively proved they were a crude hoax, and the futile efforts that have gone on to this day to convince the world that they are a fraud.

This is grim stuff. Eisner sets his scenes in the rooms where pogroms were planned, at Nazi rallies, on college campuses where protestors pass out copies of the Protocols as proof of sinister Jewish conspiracies. The last page of this, his last book, is a drawing of a synagogue burning to the ground as sheets of paper, each detailing a violent anti-Semitic incident (“July 2003 – Molotov cocktail thrown at synagogue in Allentown, Pennsylvania”), drift off the page toward the reader.

All this fits. Just as the joy and simplicity of Isaac Bashevis Singer masked the horror of his vision of a world in which devils corrupt the innocent while an absent God watches impassively, Eisner often expressed a vision of the world as a dark, cruel, and stupid place. He offers no reason why so many millions would be taken in by something so obviously fraudulent as the Protocols. He wouldn’t. He dealt with the world as it was, not in motivations or excuses. Hatred, he believed, was simply something that existed in the world. It needed to be exposed, denounced, and argued against, not explained.

Such a belief is the essence of cartooning as a serious art. Comics deal with surfaces and clear observation, not the shadowy and murky depths of the psychology of people either as individuals or as masses. Eisner understood that well, in the subjects he chose and the manner in which he chose to depict them. His figures are archetypes – all his Russian propagandists look like Trotsky, with groomed moustaches and seedy, baggy suits. His backgrounds are sketches, different shades of gray left to run together when they are not, say, the domes of Russia or the hints of bazaars on Turkish streets.

Eisner understood as a storyteller and as a graphic artist what needed to be elaborated upon, what needed merely to be suggested, and what needed to be left entirely to the eye or the imagination. That is how he helped create an art out of one of the lowest forms of junk culture.

“The Plot” is a moral act from a moral artist. Whether being the first artist to use cartoons to explain concepts to soldiers or adapting Melville into a graphic novel worthy of him, Eisner always understood the artist as having social obligations. If he had been a poet, he would have taken inspiration from Virgil and written poems that offered clear instructions on how to till a field. It is this sense of indebtedness to the world around him that his descendents would do best to take to heart.