Donald Robertson is the modern Stoic for whom the philosophy is, primarily, a working clinical tool. A practising CBT therapist with an academic background in philosophy, he is the writer who has done the most rigorous job of identifying what Stoicism and cognitive-behavioural therapy actually share — and where each can sharpen the other.
His 2010 monograph The Philosophy of Cognitive-Behavioural Therapy lays out the case in detail. Aaron Beck cited Epictetus's men are disturbed not by things but by their judgments about things as the foundational premise of CBT; Albert Ellis cited it more explicitly still. Robertson traces the specific techniques — cognitive distancing, Socratic questioning, behavioural rehearsal, exposure therapy — back to their Stoic precursors with a level of detail no other writer has attempted.
His project also runs in the other direction. CBT, in its mainstream form, has shed almost all of the philosophical commitments that made Stoicism Stoicism — the cosmology, the virtue ethics, the cosmopolitan ethics, the doctrine of fate. Robertson argues that this loss has weakened CBT; reintegrating the philosophical scaffolding gives the therapy a coherent moral horizon and the patient a framework for living, not just a kit for symptom reduction. His writing is the rare bridge between the clinical and the contemplative without collapsing either into the other.
How to Think Like a Roman Emperor is the most accessible entry point. It is structured around the life of Marcus Aurelius — his major losses, his crises of office, his philosophical practice — with each chapter paired to a specific CBT-Stoic technique that the reader is invited to apply. The result is the closest thing the modern literature has to a textbook for the prokopton.
His online presence — newsletters, courses, public posts — has made him a primary teacher for a generation of contemporary practitioners. He is the one to read if you want the practice to actually change how you function in the week ahead, not just give you more material to think about.