Logos is an important term in philosophy, analytical psychology, rhetoric and religion. Originally a word meaning "word," "account," or "reason," it became a technical term in philosophy, beginning with Heraclitus, who used the term for the principle of order and knowledge in the universe.

The sophists used the term to mean discourse, and Aristotle applied the term to rational discourse.

Aristotle gave logos a different technical definition as argument from reason or logic, one of the three modes of persuasion - the other two modes being pathos, persuasion by means of emotional appeal, and ethos, persuasion through convincing listeners of one's moral competence.

Arguments from reason or logical arguments have some advantages, namely that data are ostensibly difficult to manipulate, so it is harder to argue against such an argument; and such arguments make the speaker look prepared and knowledgeable to the audience, enhancing ethos.

The Stoic philosophers identified the term with the divine animating principle pervading the universe. After Judaism came under Hellenistic influence, Philo adopted the term into Jewish philosophy. Philo, himself a Hellenized Jew, used the term Logos to mean an intermediary divine being, or demiurge. Philo followed the Platonic distinction between imperfect matter and perfect idea, and therefore intermediary beings were necessary to bridge the enormous gap between God and the material world.

The Christian concept of the Logos is derived from the first chapter of the Gospel of John, where the Logos which is often translated as “Word” is described in terms that resemble, but go well beyond, the ideas of Philo. The Gospel of John identifies the Logos, through which all things are made, as divine, and further identifies Jesus as the incarnation of the Logos.

"In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made. In him was life, and that life was the light of men. The light shines in the darkness, but the darkness has not understood it."

An excerpt from Wikipedia

Example:

"Let us begin with a simple proposition: What democracy requires is public debate, not information. Of course it needs information too, but the kind of information it needs can be generated only by vigorous popular debate. We do not know what we need to know until we ask the right questions, and we can identify the right questions only by subjecting our ideas about the world to the test of public controversy. Information, usually seen as the precondition of debate, is beter understood as its by product. When we get into arguments that focus and fully engage our attention, we become avid seekers of relevant information. Otherwise, we take in information passively--if we take it in at all." - Christopher Lasch - The Lost Art of Political Argument