Volume one of Søren Kierkegaard’s Either/Or explores the crisis of the modern secular void—with its attendant doubt, ennui, and alienation—from the first-person perspective of an aesthete who, lacking any epistemic or moral foundations, grows increasingly obsessed with what he calls “the interesting.” In a close explication of the history of that aesthetic concept and a thorough exegesis of this volume, Kierkegaard’s Concept of the Interesting: The Aesthetic Gulf in Either/Or I explores the aesthete’s views on beauty, opera and music, tragedy and comedy, time, unhappiness, the difference between suffering and pain, boredom, eroticism, deception, and seduction, along with the ways in which these precipitate the ambition for increasingly interesting experiences. In this examination, Anthony Eagan thoroughly reveals Kierkegaard’s own perspective on how an exclusively aesthetic attitude can lead to an ever-more voracious tendency to interpret the world in a private, self-defeating, and unscrupulous fashion—one arising from and ultimately leading to moral solipsism and despair. This book develops a comprehensive understanding of Either/Or I that is crucial for understanding the rest of Kierkegaard’s authorship.