The essay is one of the great inventions of the human mind. It can talk about anything and everything. It can be lightsome or solemn. It can be witty or informative. Above all, it is short. It likes the passage in which Socrates told Callicles in the Gorgias to make his answers brief. Yet, we can find in essays things we need and want to know. Aquinas often managed to make the most profound arguments in two paragraphs. Samuel Johnson did the same.        The Classical Moment is, indeed, a collection of "selected essays." Such a collection is a classical and beloved form of English letters, the literary form most preferred by Schall.      The essays in this book all touch on knowledge and its pleasures. Schall does not tarry on the effort and determination it often takes to say just what we want to say, then say it and know that we have said it. Somehow, when an essay is written, an author simply knows that it is complete, that it is what he wanted to say. He says to himself, "Yes, that is it." An essayist may well be conscious that when he begins an essay, he really does not know what he will finally say. The writing is the saying. Our writing is our thinking, our thinking-through, our being pleased to know this is it . . . this is the point Schall, one of America's greatest essayists, makes here.       The "classical moment" is that intense experience of seeing or hearing or encountering some vista, or song, or person that takes us out of ourselves. We are most ourselves somehow when we are most outside of ourselves, seeing what is not ourselves. We are intended to be more than ourselves in being ourselves, to know with others what is the truth, to know what is.       These essays originally appeared in regular columns done in various journals, papers, and on-line sources. One can read them in any order. The order of the author or collector does have a certain "logic," but each essay is also a whole, something contained within itself.       The unity of an essay collection is found more in a kind enthrallment that comes to us when we deal with the things that are both important and delightful. At bottom, these essays belong together. Aristotle warned us that if we did not delight in the things that are, we would seek our highest pleasures where they are not really found.         We will always seek something to delight in. What civilization is about lies in finding what is really worthy of the capacity of delight that is given to us in our being. The "classical moment" is the perfect phrase that brings us to the threshold of this experience. We have to enter it ourselves, but once inside, we will find so much more than ourselves. And we will rejoice.