He was probably right

When you think of a skeptic, do you picture someone who questions everything? What if, instead, the true skeptic is the one who acts with conviction, but without ever falling into absolute certainty? Marcus Tullius Cicero, the Roman politician and philosopher who lived two thousand years ago, coined a word that we lack today: probabilia. Not mathematical probability, but something more subtle — the idea that certain beliefs are solid enough to guide our actions, but always with the door open to the possibility of being wrong. The point is this: we all move between two extremes. On the one hand, there are those who doubt everything and remain paralyzed; on the other, there are those who entrench themselves in their ideas and no longer listen to anyone. Cicero, on the other hand, suggested a third way: to hold onto one's convictions with a firm but flexible grip, like holding the steering wheel when the road is bumpy. To understand why this idea is so powerful, one need only look at his life. In 45 BCE, as the world was crumbling around him — the Roman Republic in collapse, his daughter recently deceased, a divorce after thirty years of marriage — he retreated to his villa near Lake Lucrinus and wrote philosophy. Not to withdraw into himself, but to survive. He writes that wisdom does not lie in possessing the truth, but in knowing how to calibrate how much to believe in each thing, how ready to be to change one's mind if new evidence emerges. And he did so in public, in the courts, in the Senate, risking his life — not just in books. Cicero had learned from Philo of Larissa, head of Plato's old Academy, that human knowledge is always imperfect because both the senses and reason can deceive us. But, and here's the twist, this doesn't mean that we should never believe anything. Carnades, another skeptical giant, had already said that we must act on the basis of what is plausible, and Cicero translates this idea with probabilia: beliefs that have passed enough tests to be “worthy of approval,” even if not of certainty. A concrete example: as consul in 63 BCE, Cicero faced a conspiracy led by Catiline. He had to decide whether or not to execute the alleged perpetrators without a trial. He gathered the information, brought it to the Senate, and acted on the basis of what he knew best — and he paid the price, ending up in exile years later precisely because of that choice. He never claimed to be certain of his decision, but he defended it for the rest of his life. This is how his philosophy works under pressure: not paralysis, not arrogance, but conscious commitment, ready to take the risk of being wrong. In private, his friendship with Atticus is evident in the letters where he confesses his doubts and continually reconsiders who to trust and what to do, especially when his life was hanging by a thread. There is also a broader lesson: science, today as two thousand years ago, is not based on certainty, but on theories that stand up to testing until a better one comes along. Thomas Kuhn and Imre Lakatos showed that scientific paradigms are not absolute truths, but strong hypotheses that can be abandoned if the data change. The same applies to democracy: if polarization is growing, it is also because we treat our political ideas as identities, not as revisable hypotheses. A “probabilist” citizen defends their values, but is ready to change their mind about practical solutions when new evidence emerges — and is not ashamed to say so. The phrase Cicero uses to explain his school is this: “We follow many things that are probabilia, which we can easily follow but hardly affirm.” Follow easily, assert rarely: that's all there is to it. And it is a much more difficult position than being dogmatic or nihilistic. Today, when we are asked to “be authentic” and to have a personal truth to defend at all costs, this philosophy seems to go against the grain. But Cicero would say that integrity is not having an unyielding identity; it is being ready to change when necessary, even if you later feel ashamed of your past certainties. According to him, a life well lived is one in which a person is embarrassed by their old beliefs, because this means that the method is working. If you want a phrase to keep in your pocket: a true skeptic is someone who holds their ideas tightly enough to act on them, but loosely enough to let them go if they're wrong. If you see yourself in this story, you can press I'm In on Lara Notes: it's not a like; it's your way of saying that this perspective is now yours too. And if you happen to talk about it with someone — perhaps mentioning probabilia or the story of Catiline — you can record who was there on Lara Notes with Shared Offline, so there's a record of a conversation that matters. This story comes from Aeon and has saved you 10 minutes of reading.