Donald Robertson is a cognitive-behavioural psychotherapist, trainer and writer. He was born in Ayrshire, Scotland, and, after living in England and working in London for many years, emigrated to Canada, where he now lives. Robertson has been researching philosophy and applying it in his work for twenty years. He is one of the founding members of the non-profit organization Modern Stoicism. Robertson is the author of several academic texts and multiple trade books, including the bestselling How to Think Like a Roman Emperor.