Doubt is intrinsic to our situation as beings immersed in a world that connects us to people at the same time that it renders impossible the certainty of knowing their minds. It has both an affective side that is linked with such kindred emotions as fear, anxiety, and suspicion, and a cognitive side that is engaged with questions about whether the things we perceive can lay claim to being knowledge. As such, it is central to some of the most persistent concerns of Western philosophy. The epistemic and emotional registers of doubt have a long history, but it is also a history that has not yet been plotted. The purpose of this essay is to stake out some parameters for such a study by establishing Homer's Iliad as an exemplary text. I then extend my inquiry into the relationship between doubt and portrayals of subjectivity and to two plays, Sophocles' Philoctetes and Shakespeare's Othello, which share with the Iliad an interest in the unraveling of heroism in a world torn by friendship, love, and the obsession with masculine honor. The bond between the Iliad and Philoctetes is close, since Sophocles is exploring the limitations of the Achillean paradigm in this play. In doing so, he helps shape the Greco-Roman heroic ideal that is later embodied in medieval romance, a tradition on which Shakespeare draws in Othello.