This dissertation sets early modern tragedy in dialogue with current research in cognitive psychology in order to study the cognition and behavior of four tragic heroes of the greatest early modern tragedies: William Shakespeare's Othello and Titus Andronicus, Christopher Marlowe's Doctor Faustus, and Thomas Kyd's The Spanish Tragedy. These plays have been selected as objects of analysis because, as especially revealing examples of what I am calling tragedies of the mind, they dramatize fundamental characteristics and biases of human cognitive functioning in especially acute form. In each play, the playwright's interest in highlighting a protagonist's catastrophic errors in judgment leads to especially subtle and penetrating anatomizations of the interplay between emotion and cognition, motivation and decision-making, desire and action. More than most other plays of the period, these plays are preoccupied with exploring not just the mental and emotional states of the protagonists in the process of their downfall, but also with understanding the very nature of these operations. As I argue, the relation between emotion and cognition is perhaps the most important issue in the study of motivation and decision-making in early modern tragedy because a careful analysis of pertinent works by Shakespeare, Kyd, and Marlowe reveals that these tragedians produced dramatizations of human motivation and action that seem intuitively to anticipate a great deal about contemporary insights and approaches within cognitive psychology. Since an outstanding feature of these early modern tragedies is their preoccupation with human nature—that is, with the fundamental moral and intellectual capacities of the human being—a referential framework drawn from cognitive psychology offers a potentially illuminating way of further clarifying the dramatized thought and behaviors of these tragic heroes. Such an approach to the study of literary personhood, I contend, holds the promise of revealing new insights into the drives and motivations of early modern protagonists.