Define Africanism and the theme of the book.

In Toni Morrison's literary study, Playing in the Dark: Whiteness and the Literary Imagination, Africanism has rather little to do with Africa itself and more to do with Western and specifically American notions about what blackness is. In the literary works that she studies, including several by Ernest Hemingway, blackness is both blatantly and subtly presented to define what whiteness is not. Thus, "Africanism" in these works is the savage or dark impulse to which European civilization acts as a corrective. Blackness is the space in which white characters (and authors) can contemplate their fears and desires without claiming them—instead projecting them onto black people or, more accurately, onto their ideas about black people.
In the United States, blackness meant not only the "not-free" but also the "not-me." However, Morrison's purpose in writing the short study is not to make judgments against white people, though she was disappointed in liberal critics for lacking perspicacity on exploring black identity in literature. Instead, she uses this metaphor to open up critical discussion:

I want to draw a map . . . of a critical geography and use that map to open as much space for discovery, intellectual adventure, and close exploration as did the original charting of the New World—without the mandate for conquest. I intend to outline an attractive, fruitful, and provocative critical project, unencumbered by dreams of subversion or rallying gestures at fortress walls.