Jon Stewart is a paralyzed man. Intelligent, articulate, perceptive, he nonetheless cannot commit himself to expressing what he considers the true, the good, and the beautiful. For someone about to lead a rally on Washington, D.C., this is bad news.

But wait, Stewart always says when someone calls him on his smirking irony, “I’m just a comic! Don’t look to me for answers! I’m not supposed to be serious!” But here’s the thing: comedians have often been deeply penetrating critics of society and culture, and in doing so have gotten to timeless truths about human beings. Stewart is something of a coward in that he has never gone deeper with his material. He is a victim, as well as perpetrator, of the smug decadence of the liberal West, which valorizes choice and irony above all else, even truth. But endless irony means never settling on anything as true. It means not choosing at all. “Daily Show” watchers are always keeping a tally on how often he whacks the left versus how often he whacks the right, somehow believing that sarcasm doled out equally would get to the truth of things. Stewart is a glib dancer who doesn’t ever stop long enough to declare what he believes to be true.

The most compelling book I have read this year is called “Whittaker Chambers: The Spirit of a Counterrevolutionary” by Richard Reinsch. In it, Reinsch convincingly makes the claim that modern man’s problems stem not from totalitarian impulses and regimes like fascism and communism, but from an Enlightenment philosophy that pre-dates and causes these movements. The Enlightenment, Reinsch compellingly argues, elevated reason and choice to the exclusion of the reality of man as a spiritual being — and thus became unreasonable. Enlightenment reason and rationality, taken to an extreme, argues that man creates his own reality instead of discovering timeless truths. Taking the forms of communism and Nazism, it becomes a form of insanity. Today, it has become incapable of seeing the spiritual values in suffering, or limits, or mortality. It is utopian, disregarding history and human nature. It is, in short, the kind of liberalism that Stewart and his fans represent. Seriously, does anyone expect Jon Stewart to appear at his “Rally to Restore Sanity” and announce that it is intrinsically wrong to overtax people? That it’s wrong to kill babies? That we should not expect the government to care for us our entire lives?

This makes Stewart’s an incoherent philosophy. Marches on Washington are forums for proclaiming truths about human beings, truths that are more often than not tied to ideas about God, morality, and the common good. It is a time and setting that should encourage aiming for the fences. Stewart, trapped by his own smirk, has no choice but to bunt. One thinks of his famous confrontation with Tucker Carlson a few years back on “Crossfire.” Stewart came on the show looking deeply sad and troubled. “Partisan political hacks” like Carlson and co-host Paul Begala, he said, were “hurting us.” How? Stewart couldn’t give a coherent answer, which would have meant stating a truth and defending it. He could have said to Paul Begala: “Liberals have been defending abortion for 40 years, when the human conscience and science have revealed that that is indeed a child in there.” Or he could have said to Carlson: “Conservatives fight the minimum wage — do you think it is moral to pay someone a dime to paint your house?” Stewart could have engaged. Instead, he kept his shield of irony in place, which led to a pathetic enervation. He looked sorrowful, but his answers to direct question were flaccid and nebulous. You guys are hurting us. How? Um…“stop hurting us.” To the postmodernist, liberty means endless choice, and a scolding of those one disagrees with without having to settle on anything one considers true. It is, in fact, a form of slavery. Saddled with endless choice and crippling irony, they allow themselves to break every taboo except for the taboo of earnestness — not to mention facts and moral truths they find uncomfortable.

Stewart is a penultimate postmodern liberal and ironist. In order to maintain that, he cannot settle on anything he considers irrefutable truth. Living in a world of endless political and cultural targets to mock, he can’t brandish someone or something for unqualified praise. And the I’m-just-a-comic pose is getting weaker as an excuse, not to mention corrupting his innate intelligence.

I grew up listening to Robert Klein, Richard Pryor and George Carlin. Brilliant satirists and ironist all, but they would also punch through the routine and grasp at the true and the good. In his book “The Amorous Busboy of Decatur Avenue,” a remarkably lucid and serious book for a comedian, Klein recounts meeting a woman from Germany in the early 1960s. Klein’s hip friends dismiss her horror stories about East Berlin, and he scolds them for their political naiveté. Richard Pryor’s work was pure genius, in part because of his underlying anger at the terrible brutality of racism. I still remember the bit where Pryor was talking about adoption and suddenly said, with dead seriousness, “Look, I’m all for adoption, but they got ten million [n-word] down there that need to be adopted!” His moral outrage was palatable. George Carlin would sometimes break off from jokes entirely to launch a political rant — most often an incoherent lefty diatribe, but you knew where he stood. One could easily imagine any of these men addressing a political rally. Oh, there would be jokes, but through the jokes there would be defenses of what they considered to be true.

With Stewart, there’s been no indication that there is deep, honest belief about things that are not funny. At the rally in Washington, he will be caught in a postmodern no man’s land. If he does a stand-up routine, it will be…a stand-up routine. If he gets serious, he will diffuse the irony that has made him a hipster icon. The later would be a welcome change, at least if it were not in defense of liberal untruths. If it’s somewhere in between tired Enlightenment smugness and liberal boilerplate, tens of thousands of people will have come hundreds of miles to Washington to watch a live episode of “The Daily Show.”

Mark Gauvreau Judge is the author of several books, including Damn Senators and God and Man at Georgetown Prep. His articles and essays have appeared in various publications.