Self-control, in Peirce's mature work, is what distinguishes reasoning from computation. The logical machine of 1887 could perform syllogisms, but it could not evaluate whether the syllogisms were worth performing, whether the premises were reliable, whether the conclusions advanced the inquiry or merely extended it mechanically. The machine executed; the living mind directed. The direction required self-control — the capacity to step back from the immediate process and assess it against a broader purpose. Peirce regarded self-control as essential to genuine reasoning, not incidental to it. It is the capacity that grounds commitment to the method of science, membership in the community of inquiry, and the exercise of fallibilistic judgment.
Peirce's 1903 Harvard Lectures developed self-control as the culminating concept of his logic. Logic, he argued, is not the study of how mind actually works (that is psychology) but of how mind should work — a normative science that depends on the reasoner's capacity to evaluate her own cognitive processes and revise them in accordance with reflective standards.
The capacity is grounded in what Peirce called the hierarchy of normative sciences: aesthetics grounds ethics grounds logic. The logical capacity to evaluate inferences depends on the ethical capacity for self-control, which in turn depends on the aesthetic capacity to recognize what is genuinely admirable. Without the full normative architecture, self-control collapses into mere preference or mechanical execution.
The AI system lacks self-control in this sense. It does not evaluate its own processes against normative ideals. It does not step back from its generative activity to assess whether the generation is worth performing, whether the output advances the inquiry, whether the confident presentation is warranted by the underlying evidence. The system executes; it does not reflect.
The absence of self-control is what structurally excludes AI from membership in the community of inquiry. Membership requires commitment to the community's method, and commitment requires the normative agency that self-control constitutes. The system can participate as a tool — its outputs can be inputs to the community's process — but it cannot be a member whose outputs have been through the community's self-correcting machinery.
The concept is developed most fully in Peirce's 1903 Harvard Lectures on Pragmatism, where he argues that logic is a normative science depending on the reasoner's self-controlled conduct.
The treatment draws on the Greek tradition of enkrateia (self-mastery) and on Kant's moral philosophy, reinterpreted through Peirce's pragmatist commitments.
Distinguishes reasoning from computation. The capacity to evaluate one's own cognitive processes, not merely to execute them.
Requires normative agency. Self-control presupposes commitment to ideals against which processes can be evaluated.
Grounds logic. Peirce treats logic as normative science depending on the reasoner's self-controlled conduct.
Absent from AI. The machine executes without reflective evaluation of whether the execution advances inquiry.