AbstractDescartes's approach to practical judgments about what is beneficial or harmful, or what to pursue or avoid, is almost exactly the opposite of his approach to theoretical judgments about the true nature of things. Instead of the cautious skepticism for which Descartes is known, throughout his ethical writings he recommends developing the habit of making firm judgments and resolutely carrying them out, no matter how doubtful and uncertain they may be. Descartes, strikingly, takes irresolution to be the source of remorse and repentance, of vice, and of a weak soul. In order to explain its dangerousness, this essay offers an analysis of irresolution as a failure of the will to determine itself to follow a judgment in the face of ignorance or uncertainty. This analysis connects irresolution to weakness of will and explains why Descartes regards resolution as an essential component of virtue.