This dissertation is a comparative study of the concept of innocence in three modern novels: Don Quixote (1605), The Idiot (1868) and Billy Budd (1891). Examining a range of classic religious and literary texts from the Hebrew Bible to Paradise Lost, it draws attention to a little known counter-narrative that views innocence not as an Edenic state of moral perfection prior to the acquisition of knowledge but rather as a rare and virtuous state of the soul that can be sought. This dissertation argues that Cervantes, Dostoevsky and Melville fundamentally reshape our understanding of innocence by reviving and re-animating an ancient meaning of innocence as a virtuous way of life. They explore the consequences of innocence while also giving innocence tremendous scope for imagination, knowledge and aesthetic creativity, fundamentally upending and challenging our traditional understanding of innocence as a blithe state of ignorance and bliss. The dissertation is divided into three parts. Part I analyzes a variety of meanings of innocence in the Hebrew Bible, the New Testament and in a selection of early Christian writings. It establishes the religious grounds for viewing innocence as a virtuous state of the soul while suggesting that the gradual identification of innocence with the historical state of Eden represents a genuine loss of complexity in how innocence is understood in the Bible. Parts II & III are devoted to literary portraits of innocence, including Dante's Purgatorio, Milton's Paradise Lost and the three modern novels that are the primary focus of this study. The dissertation shows how each of these modern writers understand innocence as a moral virtue closely resembling Augustine's view of innocence as "the whole of righteousness." It establishes how Cervantes, Dostoevsky and Melville employ innocence as an anti-modern symbol to challenge modernity's overvaluation of knowledge and its oversimplification of the morally pure. And it explores the perils of innocence and argues that for Cervantes, Dostoevsky and Melville innocence is a form of moral perfection that, although it may temper the ills of modernity, is nevertheless a form of life ultimately unsuited to the modern world.