It is hard to imagine a time more completely presentist than our own, more tethered to the immediate; and is hard to imagine a person more exemplary of our presentism than the current president of the United States.

Donald Trump is a creature of the instant, responsive only and wholly to immediate stimulus – which is why Twitter is his exclusive medium of written communication, and why when he speaks he cannot stick to a script. In this respect he differs little from anyone who spends a lot of time on social media; the social media ecosystem is designed to generate constant, instantaneous responses to the provocations of Now.

We cannot, from within that ecosystem, restore old behavioral norms or develop new and better ones. No, to find a healthier alternative, we must cultivate what the great American novelist Thomas Pynchon calls “temporal bandwidth” – an awareness of our experience as extending into the past and the future.

In Pynchon’s 1973 novel Gravity’s Rainbow, an engineer named Kurt Mondaugen explains that temporal bandwidth is “the width of your present, your now … The more you dwell in the past and future, the thicker your bandwidth, the more solid your persona. But the narrower your sense of Now, the more tenuous you are.”

If we want to extend our bandwidth, we begin with the past, because exploring the past requires only willingness. Recently, I was teaching the Epistles of the Roman poet Horace to a group of undergraduates. Though Horace comes from a world alien in so many ways to ours – and though he would surely fail any possible test of political correctness of the left or right – we found ourselves resonating powerfully with his quest for “a tranquil mind”. Indeed, Horace recommends just what I am arguing for now: “Interrogate the writings of the wise,” he counsels his friend Lollius Maximus:

“Asking them to tell you how you can

Get through your life in a peaceable tranquil way.

Will it be greed, that always feels poverty-stricken,

That harasses and torments you all your days?

Will it be hope and fear about trivial things,

In anxious alternation in your mind?

Where is it virtue comes from, is it from books?

Or is it a gift from Nature that can’t be learned?

What is the way to become a friend to yourself?

What brings tranquility? What makes you care less?”

(This from David Ferry’s marvelous translation.) Horace doesn’t tell you that you need to delete your social media accounts or somehow stop worrying about economic precarity. He’s asking questions here – but they are the right questions, questions that re-orient us to other possibilities for living than the ones handed to us each morning when we pick up our smartphones. “The past is a foreign country; they do things differently there,” in LP Hartley’s famous line, which of course doesn’t mean that what “they do” is always right – but awareness of it is always illuminating.

To read old books is to get an education in possibility for next to nothing. Watching the latest social media war break out, I often recall Grace Kelly’s character in High Noon, a Quaker pacifist, saying: “I don’t care who’s right or who’s wrong. There’s got to be some better way for people to live.” (That by the end of the movie she abandons her pacifism only emphasizes, if ironically, the importance of her point.) The suspicion that there’s got to be some better way has the welcome effect of suppressing the thoughtless, kneejerk reflexion that is a byproduct of our age.

To increase your temporal bandwidth in the direction of the past is to make yourself less vulnerable to the cruelties of, for example, descending in wrath on a young woman whose clothing you disapprove of, or firing an employee because of a tweet you didn’t take time to understand. You realize that you need not obey the impulses of this moment – which, it seems safe to say, tend not to produce a tranquil mind.

Another benefit of reflecting on the past is awareness of the ways that actions in one moment reverberate into the future. You see that some decisions that seemed trivial when they were made proved immensely important, while others which seemed world-transforming quickly sank into insignificance. The “tenuous” self, sensitive only to the needs of This Instant, always believes – often incorrectly – that the present is infinitely consequential. That frame of mind is dangerously susceptible to alarmist notions, like the idea that “2016 is the Flight 93 election: charge the cockpit or you die” – a claim that many Trump supporters accepted as gospel, without even inquiring what “die” might mean in that context.

Only a severe constriction of temporal bandwidth could make such a claim seem even possible. I did not vote for Hillary Clinton and cannot envision circumstances in which I would have done so, but the idea that her election would mean death (even metaphorical death) for conservatives and Christians is absurd. It would, rather, have meant the continuation of the centrist policies of her predecessor. The idea that the United States in 2016 was faced with a choice between Trump and Death, an idea driven by ignorance of even the recent past, also had the effect of disabling care for the future.

What will Trump’s policies do to international trade? What will they do to immigrant families, including those in this country legally? What will they do to the increasingly toxic state of race relations? What will they do to the health of the planet? The Trump-or-Death binary dismissed all those questions as irrelevant, and we are living with the consequences.

But these questions are essential, if we are to extend our temporal bandwidth into the future as well as the past. (And the refusal of them shows how indifference to the past makes it impossible to consider the future.) I am a Christian, and I have been dismayed at how easily many of my fellow Christians have cast aside their long-held convictions, merely to exchange their rich birthright for a cold serving of Trumpian triumphalism. As David French recently wrote in National Review, in an open letter to his fellow evangelicals: “Soon enough, the ‘need’ to defend Trump will pass. He’ll be gone from the American scene. Then, you’ll stand in the wreckage of your own reputation and ask yourself, ‘Was it worth it?’ The answer will be as clear then as it should be clear now. It’s not, and it never was.”

The bitter irony here is that so many American Christians, who often claim to have “an eternal perspective”, turned out, in 2016, to have no perspective beyond that of the immediate moment. They have left their own future, and that of the country they claim to love, uncared for and unreflected on. Someday, along will come some politician they despise whose personal morality will be even more contemptible than Trump’s, and they will be reduced to silence – or, if they insist on speaking out anyway, will merely testify to their own rank hypocrisy. “Was it worth it?”

Forty years ago, the German philosopher Hans Jonas, in a book that would prove a vital inspiration for the Green movement in his country, asked a potent question: “What force shall represent the future in the present?” In other words, what laws and norms will embody our care for those who come after us, including those already here and those yet to be born? But this is a question that we cannot ask if our thoughts are imprisoned by the stimulation of what rolls across our Twitter and Facebook feeds.

Pynchon’s Mondaugen comments on the personal tenuousness of those who live only in the moment: “It may get to where you’re having trouble remembering what you were doing five minutes ago.” And of course, no person so afflicted can recall, much less be accountable for, what he said yesterday, which is why those who work for Donald Trump have had to learn that yesterday’s truth is today’s lie, and today’s lie will be tomorrow’s truth.

But, again, Trump didn’t create this situation: he found in social media and soundbite TV news an environment ready-made for the instincts he already possessed, an environment in which tenuousness is less a condition to lament than the primary instrument of ultimate celebrity and ultimate power. Trump may be 71 years old, but he is the future of our collective temperament – unless we develop some temporal bandwidth. It’s best that we start now.

• Alan Jacobs is Distinguished Professor of Humanities in the Honors Program at Baylor University in Waco, TexaS