The word was used in Greek philosophy, and such discussions are still influential today. In Aristotelian ethics, for example in the Nicomachean Ethics, it is distinguished from other words for wisdom and intellectual virtues – such as episteme and techne. Because of its practical character, when it is not simply translated by words meaning wisdom or intelligence, it is often translated as "practical wisdom", and sometimes (more traditionally) as "prudence", from Latin prudentia. Thomas McEvilley has proposed that the best translation is "mindfulness".
In some of his dialogues, Plato showed his teacher Socrates proposing that having phronēsis is the same as being a virtuous person. By thinking with phronēsis, a person has virtue. Therefore, all virtuousness is a form of phronēsis. In the mind of Socrates phronēsis equals virtue, they are the same thing. Being good, is to be an intelligent or reasonable person with intelligent and reasonable thoughts. Phronēsis allows a person to have moral or ethical strength.
In Plato's Meno, Socrates explains how phronēsis, a quality synonymous with moral understanding, is the most important attribute to learn, although it cannot be taught and is instead gained through the development of the understanding of one's own self.
In the 6th book of his Nicomachean Ethics, Plato's student and friend Aristotle famously distinguished between two intellectual virtues: sophia (wisdom) and phronesis, and described the relationship between them and other intellectual virtues. Sophia is a combination of nous, the ability to discern reality, and epistēmē, a type of knowledge which is logically built up and teachable, and which is sometimes equated with science. This involves reasoning concerning universal truths. Phronesis involves not only the ability to decide how to achieve a certain end, but also the ability to reflect upon and determine good ends consistent with the aim of living well overall.
Aristotle points out that although sophia is higher and more serious than phronesis, the highest pursuit of wisdom and happiness requires both, because phronesis facilitates sophia. He also associates phronesis with political ability.