How do philosophers distinguish a lie from a mistake?

Philosophers distinguish a lie from a mistake primarily through the concept of intent.1

Under the paradigmatic analysis of lying, such as that proposed by St. Augustine, a lie is defined as a statement that the speaker believes to be false and that is intentionally directed at another person to cause them to accept that statement as true. In this framework, the moral and logical weight of a lie rests on the speaker's deliberate aim to induce a false belief in the receiver.1

Conversely, a mistake occurs when a person communicates information they believe to be true, even if that information is factually incorrect. Because the speaker lacks the intent to deceive—and indeed believes they are conveying the truth—the act does not meet the criteria for a lie.1

While some modern theorists debate the nuances of this definition—such as whether a lie must be verbal or if it can include nonverbal acts of deception—the fundamental distinction remains: a lie requires a conscious, deceptive intent, whereas a mistake is an error made without the desire to mislead.1