habits of speech and gait, and a smile of "inexpressible benignity". He was known to talk to himself, a habit that began during his childhood when he would smile in rapt conversation with invisible companions. He also had occasional spells of imaginary illness, and he is reported to have had books and papers placed in tall stacks in his study. According to one story, Smith took Charles Townshend on a tour of a tanning factory, and while discussing free trade, Smith walked into a huge tanning pit from which he needed help to escape. He is also said to have put bread and butter into a teapot, drunk the concoction, and declared it to be the worst cup of tea he ever had. According to another account, Smith distractedly went out walking in his nightgown and ended up outside of town, before nearby church bells brought him back to reality. James Boswell, who was a student of Smith's at Glasgow University, and later knew him at the Literary Club, says that Smith thought that speaking about his ideas in conversation might reduce the sale of his books, so his conversation was unimpressive. According to Boswell, he once told Sir Joshua Reynolds, that "he made it a rule when in company never to talk of what he understood". Smith has been alternatively described as someone who "had a large nose, bulging eyes, a protruding lower lip, a nervous twitch, and a speech impediment" and one whose "countenance was manly and agreeable". Smith is said to have acknowledged his looks at one point, saying, "I am a beau in nothing but my books." Smith rarely sat for portraits, so almost all depictions of him created during his lifetime were drawn from memory. The best-known portraits of Smith are the profile by James Tassie and two etchings by John Kay. The line engravings produced for the covers of 19th-century reprints of The Wealth of Nations were based largely on Tassie's medallion. Religious views Considerable scholarly debate has occurred about the nature of Smith's religious views. Smith's father had shown a strong interest in Christianity and belonged to the moderate wing of the Church of Scotland. The fact that Adam Smith received the Snell Exhibition suggests that he may have gone to Oxford with the intention of pursuing a career in the Church of England. Anglo-American economist Ronald Coase has challenged the view that