The soothsayers are people who could foresee the future and who provided information to others based on what they saw. The classical soothsayer Tiresias from the Oedipus cycle is one example, and Michael Scot, the medieval polymath. There is a distinction between charlatans who only claim to know the future and those who are indeed gifted with foresight. In the medieval period, not all foretelling or prophetic gifts would have seemed illicit.

In Dante's Inferno, the soothsayers occupy the 20th canto, among other sins involving fraud. Dante presents fraud as more dangerous to human society and more dangerous to the sinner's soul, compared to sins of appetite or desire and sins of violence. Fraud plays upon others' minds and on their trust of others. When this trust is violated, so too is their capacity to love other people in the way that God expects.

The other reason that Dante suggests soothsayers are more serious sinners is because they seek to deprive the human of his or her choice. Choice, says Virgil early in the journey, is the "good of the intellect," and the poem is designed to illustrate the need to choose rightly, and to reject false appearances. To damage a person's ability to make an authentic choice--by leading them to believe that a future event is already a foregone conclusion--tampers with their choice and therefore their authentic self. They may fail to strive to become the person they should be if they believe the striving has no effect on their eventual outcome.

Soothsayers are fortune tellers, or people who claim to be able to predict the future. In Canto XX, Dante and Vergil encounter these souls, forced to walk with their heads forever facing backwards. Fortune-telling was considered a form of black magic or witchcraft, and was a form of heresy according to the Church. The punishment, like so many in Inferno, is cruel but in poetically just. Having spent their lives attempting to see the future, they must now always look back. Dante weeps to see these men contorted and tormented so.