Imagination is unruly. It creates the mind's world, linking the sensory realm to the realm of the intellect by oscillating between mind and body, self and world, ideal and real. It has been construed as both essential to rational thought and as a dangerous impediment to it. Alexander Schlutz demonstrates that this ambivalence in conceptions of imagination informs fundamental philosophical and aesthetic projects of European modernity. By analyzing the discourse about imagination in the philosophical systems of Plato, Aristotle, Descartes, Kant, and Fichte, as well as in the works of the Romantic poet-philosophers von Hardenberg (Novalis) and Coleridge, who champion discourse about imagination as a prime aesthetic and poetic principle, Schlutz explores how the imagination is haunted by the presence of the faculty's dark twin, fantasy, which is conceived as a danger (rather than a supplement) to human rationality and hence threatens to undermine the Cartesian subject that is grounded in rational, logical thought. Alexander M. Schlutz is associate professor of English at John Jay College, City University of New York.