On the anatomy of probabilism

Abstract

Scholastic probabilism emerged as a revolutionary framework for moral decision-making under uncertainty, diverging from the medieval requirement to follow the most probable or safest course of action. Initiated in the late sixteenth century, the doctrine asserts that any rationally defensible opinion may be adopted as a premise for action, even if its alternative is supported by weightier reasons. This shift rests on an information-centered rationale intended to limit the costs of moral deliberation and a liberty-centered rationale derived from legal principles such as in dubiis melior est conditio possidentis. By treating the human will as being in possession of its natural freedom, probabilism places the burden of proof on the moral law rather than the agent. This quasi-juridical conception of ethics—viewing morality as a set of law-like constraints on negative liberty—serves as a primary ancestor to modern liberal individualism and the structural frameworks of both Kantianism and utilitarianism. While the eighteenth-century rise of equi-probabilism attempted a via media by reintegrating psychological weightings of probability, it ultimately abandoned the strictly juridical anatomy of the original doctrine. Contemporary neglect of this tradition obscures the historical roots of modern moral philosophy and the persistent difficulty of justifying moral restrictions within pluralistic frameworks. – AI-generated abstract.