This article argues that Virginia Woolf's theory and practice of the novel extends key elements of the gothic sublime shared by nineteenth-century sensation fiction and by contemporaneous psychiatric methods of diagnosis. In novels such as Wilkie Collins's The Woman in White and Mary Elizabeth Braddon's Lady Audley's Secret, sensation heroes find access to hidden mental reality through the psychologically revealing power of painted portraits. By doing so, they enact a distinctly gothic version of the sublime, offering a glimpse into the dark psyche by means of a subject's awed inability to conceive its magnitude. Similarly, by relying on the fantastic power of vision he found in paintings and photographs, Jean-Martin Charcot developed into medical knowledge the gothic sublime, which also aided the detective protagonists of sensation novels. Working to extend this tradition, Woolf in To the Lighthouse uses the logic of the gothic sublime as a model for exploring human character. The gothic sublime illuminates in Woolf's theory of consciousness a striking functional resemblance between the mimetic realism of photography and the abstract representations of formalist art. By virtue of the insufficiency of simple perception, both aesthetic modes offer, for Woolf, a window into the very depths of human psychology.