Ian Stewart (1) is the professor of mathematics Ian N Stewart (b. 1945-), and co-author of books with Jack Cohen. He is also the author of Wheelers and Heaven. Ian Stewart (2) b. 1928- and Ian Stewart (3) b. 1966- are both journalists. Although they appear as one author on the website of publishers Allen & Unwin, their biographical details reveal them to be different people.(4) Stewart, Ian, 1940- wrote Ta Today: A New Introduction to Transactional Analysis.