The Adem are a reclusive warrior culture living in the harsh, wind-swept region of Ademre, far to the east of the civilised Four Corners. Their society is built around the Lethani - a philosophical concept that governs right action, somewhat analogous to a martial code of ethics but far more nuanced and difficult to articulate. The Adem are renowned as the finest fighters in the world, practising a system of hand-to-hand combat called the Ketan, and many earn their living as mercenaries - though they consider this a practical necessity rather than a calling. Their culture has several customs that outsiders find strange: they communicate emotion through subtle hand gestures rather than facial expression, considering open displays of feeling to be barbaric, and they hold unusual beliefs about the nature of parenthood. Kvothe trains among the Adem during The Wise Man's Fear, earning the right to carry a sword named Caesura - an achievement that few outsiders have ever managed. His time in Ademre fundamentally changes his fighting ability and gives him a deeper understanding of discipline and restraint.