To understand the Stoics, I try to remember one thing: they weren’t living in history; they were living in what they viewed as the present. The same present we inhabit today, except framed by their own time, their own context. They didn’t know where things were headed any more than we do now. For them, it was a progressive time, full of uncertainties, only partially illuminated by what they could see. We, too, have only a partial view of our moment, despite all our technology and foresight.

The late historian David McCullough, in his excellent biography of Truman, once said that the hardest part of being a biographer is getting the reader to remember “nothing was ever on track.” Things could have gone any way at any point. And here’s the key line from McCullough that sticks with me: “As soon as you say ‘was,’ it seems to fix an event in the past. But nobody ever lived in the past, only in the present. The difference is that it was their present.”

This notion reveals something about how we view history—and by extension, how we see ourselves. We often look at the past as if it were written in stone, as if the events that shaped it were inevitable. But they weren’t. They were just people, living their lives, with all the ambition, fear, hope, and uncertainty we experience today. They didn’t know how things would turn out, just like we don’t. This is where the Stoic mindset becomes relevant. For them, the present was all there was, and it was their duty to make the best of it without the benefit of hindsight.

So when we study the past, we must resist the urge to treat it as a linear story that was destined to unfold in a certain way. There was a range of possibilities at every moment in history, just as there is now. People made choices—sometimes based on limited information, sometimes on fear, or even arrogance—and those choices shaped what we now look back on. But to see their actions as a set series of events is to miss the point.

This is not to say that we should never judge the mistakes or failures of the past. Of course we can, and sometimes should, but understanding the context of those decisions is key to making better choices in the present. When people in history made decisions, they didn’t have the luxury of knowing how things would turn out. They could have gone in any number of directions. Our advantage, as people living now, is that we can learn from their mistakes and successes—but only if we remain aware that we too live in an unfinished moment.

The ancient world wasn’t a distant “other time.” It was just the world for those living in it. It was filled with people who were flawed and emotional, just as we are. Their mistakes may seem obvious to us now because we know the outcomes, but these same flaws and emotions shape our decisions today. And just like theirs, some of our actions won’t age well. The key is to manage our impulses and strive to do better, strive to see as much of the picture as we can in our moment.

The past is not some distant realm that we can safely study from the outside. It’s a reminder of our shared humanity. A reminder that we must be humble because, like those who came before us, we don’t know how it will all turn out.

To live well, as the Stoics believed, is to recognize that the present is all we have. And in the words of Seneca, “It is not that we have a short time to live, but that we waste a lot of it.” Understanding this truth may be the most important history lesson of all.