James Joyce has written that 'the man of genius makes no mistakes; his errors are the portals of discovery.' In Joyces Mistakes, Tim Conley explores the question of what constitutes an 'error' in a work of art. Using the works of James Joyce, particularly Ulysses and Finnegans Wake, as central exploratory fields, Conley argues that an 'aesthetic of error' permeates Joyce's literary productions; readers and criticism of Joyce's texts are inevitably affected by a slippery dialectic between the possibility of mistake and the potential for irony. Outlining modernism's struggle with textual authority and completion, Conley locates Joyce among his literary contemporaries, including Herman Melville, Marianne Moore, Ezra Pound, and Marcel Proust. He finds that Joyce's reconfigurations of authorial presence and his error-generating methods problematize all attempts to edit, anthologize, and even quote or cite his texts. Yet Conley goes well beyond cataloguing the instances where error is at issue in Joyce's canon; he offers a comprehensive, engaging look at theories of error. He extends his analysis of Joyce to examine the radical reshaping of cognition by 'the textual condition' (McGann), and suggests that the act of reading's propensity for diversity of error makes 'misreadings' valuable critical experiments and the basis of literary theory. Joyces Mistakes is an absorbing and sophisticated work, a portal of discovery in its own right.