John McPeck is a philosopher of education best known for his subject-specificity thesis regarding critical thinking, developed in his influential 1981 work Critical Thinking and Education. He argued that critical thinking is always thinking about something within a specific domain, and therefore cannot meaningfully exist as a general, transferable cognitive skill. His position sparked sustained debate in philosophy of education about whether critical thinking can or should be taught as a standalone subject.
Developed the subject-specificity thesis: critical thinking is always domain-bound, not a general skill
Authored Critical Thinking and Education (1981), a foundational text in the field
Challenged the 'generalist' movement in critical thinking education and standardized thinking skills curricula
Provoked debate with philosophers such as Harvey Siegel and Richard Paul over the nature of transferable reasoning
Influenced curriculum theory by arguing that content knowledge is inseparable from evaluative thinking