Nick Alchin has taught IB Theory of Knowledge and mathematics since 1995, firstly at the United World College in Singapore where he also lectured in critical thinking at local universities, and then at the International School of Geneva. He is the author of two TOK books, Theory of Knowledge (meant for students), and Theory of Knowledge; Teachers Book (meant for teachers), published in late 2002 by John Murray. He is currently at Sevenoaks School, UK.