De Ira or "On Anger" is an essay on anger by Seneca the Younger. The work offers advice on controlling anger and to make it subject to reason. It is not clear to scholars who wrote the first work on the subject of passions or emotions (the terms are thought interchangeable), but while Xenocrates (396/5-314/3 BCE) and Aristotle (384-322 BCE) were students at Plato's Academy, a discussion on emotions took place which provided likely the impetus for...