Eigenvalue provides the first history of ‘eigenvalue’ by building an important bridge between the hard and the soft sciences. Originally a mathematical term, Hanjo Berressem applies Eigenvalue, which roughly translates to proper value, to the media studies discipline for the first time, providing a philological history and line of development across the sciences through to contemporary cultural studies. Berressem’s groundbreaking work is organized into 2 books, with the first book broken down into six topical areas - mathematics, physics, cybernetics, biology, literary studies, cultural studies. The second book discusses the place of eigenvalues in sound, light and literature, specifically, Alvin Lucier’s experimental composition I am Sitting in a Room, Bill Morrison’s eight-minute experimental film Light is Calling and the literary works of Thomas Pynchon. Berressem’s thought-provoking philology is an important reference point for readers seeking an authoritative introduction to a term that connects other key ideas in contemporary debate.