The examined life has been at the core of philosophical ethics since the fourth century BCE, when it emerged as a central teaching of both Socratic and Confucian thought. For these philosophers, the imperative of self-examination answered a practical rather than a theoretical question, namely: how can we best secure the good life for ourselves and others? Since then, thinkers from Seneca to Nietzche to Emerson have championed habits of self-examination as essential to living well.