Caroline Marquet, a talented painter, has endured her own dark past, but her future is about to become even darker at the hands of the man across the hall. For although Arthur lectures on kindness, he views the world through a prism of metaphysical Nature where all human desires are the work of a malevolent will. Unleashed from its theoretical constraints, the will burdens the philosopher with an aggressive pessimism, festering an obsessively vengeful relationship with Caroline which results in a missing student, criminal charges, and shattered lives.
Arthur's thesis on will, natural law, and morality, which develops through the novel, ultimately determines its outcome. Can the philosopher escape the fate he has written for himself, or must he, and indeed humankind, forever suffer In Arthur's Nature?