https://amgreatness.com/2021/02/20/can-the-truth-set-us-free/
I try to re-read The Confessions (the one by St. Augustine, not the one by Rousseau) every Lent. Since it is that time of year again, and since I am rather weary of the usual quotidian static, I thought I would avert my gaze from the armed camp on the Potomac and say a word or two about my reading. In a famous passage of Book XI of that deep and magisterial book, Augustine asks a simple but apparently imponderable question: “What, then, is time? I know well enough what it is,” he says, “provided that nobody asks me; but if I am asked what it is and try to explain, I am baffled.”
It is hard to read that passage without experiencing a shock of recognition.
There is a basic sense in which, like St. Augustine, we all know what time is. As Einstein once observed, time is “what the clock measures.” Any yet it is impossible not to feel that that answer, though correct, is somehow insufficient to the awesome reality of time—assuming, that is, that time is or has a reality and is not, as some philosophers have insisted, an illusion we contribute to make experience comprehensible.
When Plato described time as “the moving image of eternity,” his formulation was more poetic than Einstein’s, but not necessarily more satisfactory. The fact is that time, like many basic concepts, names an idea we are perfectly familiar with but that we may not be able to explain.
Consider the concept of truth.
There is an important sense in which we all know what truth is. We just couldn’t get along in the world if we didn’t. But being able to apply a concept in daily life does not necessarily mean we can define it. Or that we really understand it.
Medieval philosophers defined truth as “adaequatio intellectus et rei”: a “correspondence between thought and thing.”
That sounds impressive, especially in Latin, and it has a certain intuitive appeal. When we utter a true proposition—“2 + 2 = 4,” say, or “Snow is white”—we can see that there is a correspondence between our judgment and the state of affairs it names.
But what, exactly, is the nature of that “correspondence”?