Dissoi Logoi is a rhetorical exercise dating back at least to the 3rd century AD of arguing a topic from both sides. It is intended to help an individual gain a deeper understanding of an issue by forcing him or her to consider it from the angle of his opponent, which may serve either to strengthen his or her argument or to help the debaters reach compromise.

In ancient Greece, students of rhetoric would be asked to speak and write for both sides of a controversy. Dissoi Logoi was first referred to by name in Exhortation to Philosophy, a work from the 3rd century AD, by Syrian Neoplatonist

Neoplatonism

Neoplatonism , is the modern term for a school of religious and mystical philosophy that took shape in the 3rd century AD, based on the teachings of Plato and earlier Platonists, with its earliest contributor believed to be Plotinus, and his teacher Ammonius Saccas...

 Iamblichus. The custom has long persisted. For instance, the Wright brothers

Wright brothers

The Wright brothers, Orville and Wilbur , were two Americans credited with inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903...

, during an argument, would deliberately switch sides temporarily and each argue for their opponent's position.

Dissoi Logoi also refers to a short treatise written anonymously around 600 BC, and found among the papers of Sextus Empiricus

Sextus Empiricus

Sextus Empiricus , was a physician and philosopher, and has been variously reported to have lived in Alexandria, Rome, or Athens. His philosophical work is the most complete surviving account of ancient Greek and Roman skepticism....

.