“Virtue, then, being of two kinds, intellectual and moral, intellectual virtue in the main owes both its birth and its growth to teaching (for which reason it requires experience and time), while moral virtue comes about as a result of habit, whence also its name (ethike) is one that is formed by a slight variation from the word ethos (habit).”
– Aristotle, Nicomachean Ethics, Book II (350 BCE, Athens, Greece)
“Virtue is harder to be got than knowledge of the world: and, if lost in a young man, is seldom recovered.”
– John Locke, Some Thoughts Concerning Education (1693 CE, London, England)
“A virtue is an acquired human quality the possession and exercise of which tends to enable us to achieve those goods which are internal to practices and the lack of which effectively prevents us from achieving any such goods.”
– Alasdair MacIntyre, After Virtue: A Study in Moral Theology, First Edition (1981 CE, Boston, United States)