Experimental Visions analyzes African American conceptions of science during the first half of the twentieth century. Scholarship on race and science has proliferated in recent years, drawing attention to how epistemological regimes of objectivity have categorized people by race and rendered them knowable objects, often at the expense of their complexity and humanity. Following other recent work in Black Studies, and with specific focus on W.E.B. Du Bois, I ask what alternative formulations of “the scientific” Black thinkers have imagined historically. Historiography on Du Bois’s thought often demarcates a boundary between his earlier, ostensibly “scientific” writings, his later “activist” writings, and his career-long exercises in aesthetic and literary form. Conversely, I suggest themes that recur throughout his corpus that invite us to think about experimentation expansively as a multi-generic form of thought, emphasizing opacity and instability rather than transparency and replicability. Scientific relativity, finally, becomes not only an epistemic but a political problem for Du Bois. While Du Bois figures centrally in my work, he does not exhaust this dissertation. I also stage conversations between him and other writers like Richard Wright, Zora Neale Hurston, Langston Hughes, Anna Julia Cooper, George Schuyler, William Attaway, Kelly Miller, Ann Petry, Horace Mann Bond, Ralph Ellison, Charles S. Johnson, and C.L.R. James, forging a conceptual history of the relationship between metaphysical inquiry and political experimentation in African American thought. Exploring technology and cinema (Chapter One), comedy and vitality (Chapter Two), and tragedy, relativity, and cosmology (Chapter Three), I argue that African American and Afro-diasporic thought on science wasn’t just confined to rejecting or debating racialized conceptions of science, nor did it necessarily focus only on imagining alternative utopian or dystopian futures. Conversely, this dissertation argues that African American thinkers mobilized and critiqued frameworks of “force,” “inquiry,” “vitality,” “adaptation,” and “organicism” in ways that tethered assumptions about the nature of scientific reality to the kinds of political experiments viable at given moments.