The peculiar nature of the pandemic is that the virus is, while all too real, invisible to the naked eye and all pervasive. Covid-19 has formed itself into the structure of reality: a disease everywhere and nowhere, imprecisely known and, as yet, untreatable. And most of us have the feeling of having been swimming in a sea of virus for many weeks now, possibly months. But perhaps beneath the trembling of fear lies a deeper anxiety, the anxiety of our mortality, our being pulled toward death. And this is what we might try to seize hold of, as a condition of our freedom.

It is vitally important, I think, to accept and affirm anxiety and not hide away, flee or evade it, or seek to explain anxiety in relation to some object or cause. Such anxiety is not just a disorder that needs to be treated, let alone medicated into numbness. It needs to be acknowledged, shaped and honed into an vehicle of liberation. I’m not saying this is easy. But we can try to transform the basic mood of anxiety from something crippling into something enabling and capable of courage.

Most of us, most of the time, are encouraged by what passes as normality to live in a counterfeit eternity. We imagine that life will go on and death is something that happens to others. Death is reduced to what Heidegger calls a social inconvenience or downright tactlessness. The consolation of philosophy in this instance consists in pulling away from the death-denying habits of normal life and facing the anxiety of the situation with a cleareyed courage and sober realism. It is a question of passionately enacting that fact as a basis for a shared response, because finitude is relational: It is not just a question of my death, but the deaths of others, those we care about, near and far, friends and strangers.

A few weeks ago I found myself talking blithely about plague literature: Boccaccio’s “Decameron,” Defoe’s “A Journal of the Plague Year,” Camus’ “The Plague.” I thought I was clever until I realized a lot of other people were saying the exact same things. In truth, the thinker I have been most deeply drawn back to is the brilliant 17th century French mathematician and theologian Blaise Pascal, in particular his “Pensées.”

Pascal writes of the inability to sit quietly alone in a room as the source of all humanity’s problems; of inconstancy, boredom and anxiety as defining traits of the human condition; of the machinelike power of habit and the gnawing noise of human pride. But most of all, it is Pascal’s thought that the human being is a reed, “the weakest of nature,” that can be wiped away by a vapor — or an airborne droplet — that grips me.

Human beings are wretched, Pascal reminds us. We are weak, fragile, vulnerable, dependent creatures. But — and this is the vital twist — our wretchedness is our greatness. The universe can crush us, a little virus can destroy us. But the universe knows none of this, and the virus does not care. We, by contrast, know that we are mortal. And our dignity consists in this thought. “Let us strive,” Pascal says, “to think well. That is the principle of morality.” I see this emphasis on human fragility, weakness, vulnerability, dependence and wretchedness as the opposite of morbidity and any fatuous pessimism. It is the key to our greatness. Our weakness is our strength.

Simon Critchley is a professor of philosophy at the New School for Social Research and the author of several books, including, most recently, “Tragedy, the Greeks, and Us.” He is the moderator of The Stone.

AUDIO: Can philosophy help us navigate this moment that is marked by anxiety, fear and grief? Listen to The Stone’s editor Peter Catapano and the philosopher Simon Critchley discuss the pandemic and answer questions from readers.