Carneades (214 BC – 129 BC)

An atheist and a radical skeptic, Carneades is the first to claim that metaphysicians have failed to identify rational meanings in religious beliefs. Neither senses nor reason can allow people to acquire truth: all knowledge is impossible, except for the knowledge that all other knowledge is impossible. People manage to live and act correctly by means of probabilities of truth, the only ones that can be determined. The world is the result of chance, but human beings can freely choose what to do due to their “free movement of mind” and the ability to be the cause of their own actions.

Modern Reflection  

Carneades’s insistence that certainty is unattainable anticipates modern discussions about probabilistic reasoning, cognitive bias, and the limits of human knowledge. His idea that we must act on the most persuasive evidence rather than absolute truth resembles contemporary approaches in science, law, and everyday decision‑making. While his skepticism can seem destabilizing, it also encourages intellectual humility and flexibility in the face of incomplete information. He offers a model of freedom grounded not in certainty but in the responsible management of doubt.