Previously an agnostic, he converted to Roman Catholicism in 1909, "the only action in my life which I am quite certain I have never regretted." Speaking from personal experience, however, he once advised Belloc to "never, never, never talk theology or discuss the Church with those outside it. People simply do not understand what you are talking about and they merely (a) get angry and (b) come to the conclusion that one doesn't believe in the thing oneself and that one is simply doing it to annoy."