Karatani was educated at University of Tokyo, where he received a BA in economics and an MA in English literature. The Gunzō Literary Prize, which he received at the age of 27 for an essay on Natsume Sōseki, was his first critical acclaim as a literary critic. While teaching at Hosei University, Tokyo, he wrote extensively about modernity and postmodernity with a particular focus on language, number, and money, concepts that form the subtitle of one of his central books: Architecture as Metaphor.[citation needed]