Cicero’s method: how to hold beliefs wisely

In 45 BCE, Roman lawyer and philosopher Marcus Tullius Cicero developed a philosophy of ‘probabilia’, a method for holding beliefs that avoids both rigid certainty and unproductive doubt. He crafted this approach while facing personal and political turmoil, including the fall of the Roman Republic, a divorce, and the death of his daughter.

Cicero, originally a student of Plato, moved beyond simply relaying Greek ideas and created a Latin philosophical vocabulary.

He believed that true philosophy should be tested in real-world settings like courts and the Senate, not confined to abstract thought. Cicero distinguished his ‘Academic Skepticism’ from other skeptical schools by arguing that while certainty is elusive, we should still approve of and act on the most persuasive claims, those that have withstood scrutiny. He graded beliefs based on the level of testing they’ve survived, reserving strong convictions for ideas that have been thoroughly examined.

This contrasts with those who treat doubt as a shield against evidence or demand absolute certainty before believing anything. Cicero’s method encourages individuals to state their confidence levels, separate values from empirical beliefs, and be open to changing their minds. He practiced this approach throughout his life, even when facing threats from political rivals like Mark Antony, and maintained that being wrong should be seen as an opportunity to learn, not a disgrace.

His work continues to offer a useful method for navigating complex issues in science, democracy, and personal life.