In Sempre Susan, her very charming, recently released memoir of life with Susan Sontag, Sigrid Nunez—she was the girlfriend of Sontag’s son, David Rieff, as well as the grande dame’s youthful assistant—gives us a taste of the master’s esprit. “To read a whole shelf of books to research one twenty-page essay,” Nunez writes, channeling Sontag, “to spend months writing and rewriting, going through one entire ream of typing paper before those twenty pages could be called done—for the serious writer, this was, of course, normal. And, of course, you didn’t do it to feel good about yourself. … You didn’t do it for your own enjoyment (unlike reading), or for catharsis, or to express yourself, or to please some particular audience. You did it for literature.”

You did it for literature: Of all of Sontag’s intellectual heritage, this sentiment—expressed in various essays and interviews in various shades of austerity—may prove the most endurable. How many of us, after all, still do it for literature? How many measure, as Sontag commanded us to do, every attempted bit of writing not in light of its putative contribution to our fame and fortune but against the yardstick of absolute cultural necessity?

These aren’t rhetorical questions. Or, at least, they oughtn’t be. As technology keeps widening the boulevards down which dross marches into our computers, our smart phones, and our minds, we are surrounded by more and more evidence that Sontag’s credo is both fiercely urgent and deeply ignored. Nothing about blogs or tweets or status updates or other similar channels of immediacy encourages much thought of posterity, after all, and few, if any, wonder if the 140-character update they’re about to unleash into the ether contains anything that might be considered of service to the greater cause of human development. The very thought, likely—that what we write, that everything we write, should serve to bolster Literature, Culture, Humanity, and other capital-letter concepts—will seem, to most contemporaries, uncool. If there is anything our mediated era sanctifies it is the right—indeed, the obligation—for all to have an opinion, and to share these opinions on social networking platforms that turn them into commodities.

If this sounds to you like a bit of old-fashioned alarmist piffle, kindly avail yourself of last week’s New York Times Magazine and turn to page eight. On the bottom of the page, under the headline ”Analytics,” the newspaper printed several illustrations of envelopes, each embossed with a number. Each number represents the number of readers who had emailed the newspaper’s executive editor, Bill Keller, to call him a particular name: Eight insisted he was “a leftist,” six chose “elitist,” four cried “communist,” and 21, in true American fashion, opted for four-letter words. What’s fascinating isn’t that people, given access to email and Keller’s address, might choose to opine; that, after all, is what the Internet is for. What’s truly astounding is that the purveyor of all the news that’s fit to print would supplement its traditional letters to the editor page with such a numerical aggregate of rageful readers’ missives. What value do these slurs-by-the-numbers hold? Without context, what is a reader to learn from the mere fact that three anonymous correspondents think Keller a socialist? This is sound and fury, signifying nothing. Or worse: As we’re swept by the meaningless, easy rage—can you believe these people said Bill Keller wasn’t as smart as his daughters? The morons! For shame!—we lose track of the real, and necessary, questions we should be asking. What we need, then, is some sort of device to steer us back on path, a device like Balaam’s ass.

The hero of this week’s parasha, Balaam is a fascinating figure. Although not much is said about this seer in the Bible, the Talmud is filled with introspection and speculation about his particular powers. In Tractate Berachot, for example, Balaam’s particular and awesome powers are explained: Alone among mankind, he had the gift of divining the precise moment in which the Almighty was wrathful—even omnipotent beings are angry, every now and then, for no good reason—and making use of this knowledge to his advantage. Like cursing on command: As this week’s parasha begins, Balaam is summoned by the Moabite king Balak to cast a spell on the Israelites, an upstart nation he fears and despises. Balaam hesitates, but God appears and assures him that all is well. And so, soothed by the divine promise, and thrilled with the promise of a house filled with Moabite gold, Balaam mounts his ass and rides to meet Balak.

What happens next is too lyrical to summarize adequately. The ass sees an angel of the Lord, understands that Balaam is riding toward disaster, and stops mid-trot. Three times this happens, and three times the prophet curses the poor animal, until the ass, blessed with speech, protests, and Balaam, shocked, finally sees the angel himself and realizes his mistake. When he finally meets up with Balak, he has nothing but blessings to bestow on God’s chosen people. The Moabite is mad, but Balaam is unfazed. “What the Lord puts into my mouth,” he states, “that I must take care to say.”

Most of us, lacking a magical ass, haven’t the advantage of receiving word directly from the heavenly source. But there’s still a lesson to be learned from Balaam: Turning to Balak, the seer asks, “How can I curse whom God has not cursed, and how can I invoke wrath if the Lord has not been angered?” He understands, in other words, that anger and expletives are potent things, not mere words but vehicles for spiritual matter, and that hurling them unnecessarily and injudiciously can cause disaster. He understands, in other words, what Sontag, too, understood, and what so many of us, opining furiously online, seem to have forgotten: Words have mighty consequences, and we should give them very careful thought.