This chapter focuses on the influence of nineteenth-century neurology on Beckett’s writing, especially the work of Jean-Martin Charcot and Georges Gilles de la Tourette, who both worked at the Salpêtrière Hospital in Paris. Charcot’s famous Tuesday lectures, at which he exhibited his patients to admiring crowds, became an intellectual and middle-class pastime in Paris, instigating a new performance style in the Parisian café-concert, in cabaret, and in music hall, while the performers at such venues, in turn, became the stars of early cinema, adapting their convulsive performance style to silent film. Beckett took a lifelong interest in these popular forms, and the chapter considers the impact of their convulsive aesthetic on his work. It also addresses Beckett’s representation of speech and his reading of Bergson’s 1900 essay on Laughter, which argued that humour arises from ‘something mechanical encrusted on the living’. Bergson’s extended essay was itself substantially influenced by medical discoveries, and especially the theatrical and often spectacular culture of the late-nineteenth-century science of neurology. While Beckett diverges from Bergson’s Cartesian stance, he nevertheless concurred on the limitations of free will and agency, on ‘the deep-seated recalcitrance of matter’, and on the human as always already determined by the mechanical.