Art Brut, also termed Outsider Art, has long been suppressed from most art historical writing. Why this rejection? The hyperbolic expressions of Romanticism and Symbolism nourished a desire for derangement and dissociation that inspired both Expressionism and Surrealism. Simulated delirium became the object of the new art -- experimental, avant-garde, modernist -- which arose from the fragmented codes, the shattered forms of everyday communication. But what of those artists whose works, and often whose deliria, are the manifestations of sheer eccentricity, of social isolation and marginalization, or of madness? In this book Weiss investigates the origins of the unrestricted contemporary artistic field, seeking its sources in those works hitherto absent from the official histories of art -- works that constitute art's dark interior, its disturbing netherworld. Secluded, occluded, excluded, Art Brut nevertheless extends the limits of artistic creativity and aesthetic discourse, regardless of whatever anxieties such works may produce. Shattered Forms explores the relations between Art Brut, the psychopathology of expression, and avant-garde Modernism, attempting to show how the consideration of Art Brut should lead to a revision of our theoretical and museological paradigms.