Aristotle (c. 384-322 BCE)
“The accepted view of the magnanimous man is that his gait is measure, his voice deep, and his speech unhurried. For since he takes few things seriously, he is not excitable, and since he regards nothing as great, he is not highly strung”
- From The Nicomachean Ethics (Bekker page 1125a) by Aristotle, translated by J. A. K. Thomson (Penguin Classics, 2004).