Never before in the history of the world has there been a time like the one we are living in, when environmental, social and technological change is occurring not only at a dizzying speed, but accelerating exponentially.

Aspects of our social and physical environment that have remained stable for centuries or even millennia are now starting to warp and buckle before our eyes. Democratic institutions that have weathered two-and-a-half centuries are tottering. Ice shelfs and glaciers that are more ancient than humanity itself are melting away. Thousands of species that evolved over millions of years are vanishing. And at the same time smart phones, AI and social media are transforming every aspect of our lives at such a rate that we have become almost inured to change, caught somewhere between greed for the latest innovation, and helpless dread at what we have unleashed.

In physics, change is quantifiable, and has a name: energy. Although we tend to think of energy as an ethereal substance, it is a measure of change in physical systems. When a physical system undergoes a chain reaction in which change feeds on itself, liberating more and more energy in a self-reinforcing cycle, we call this an explosion. That, on a planetary level, is what we are living through: an explosion that began millennia ago when the brains of our ancestors underwent the evolutionary transformation that turned them into the formidable instruments of cognition and invention that they are.

As human intelligence exploded, so too did our capacity to extract and utilise energy in our environment, thus translating the intelligence explosion into the domain of matter and energy. We developed agriculture to exponentially increase the food supply and domesticated animals to harness and channel their energy into producing yet more food and more energy. Eventually we worked out how to use steam to drive engines, driving industrialisation and transforming the world faster than ever. Then we used these machines to dig up fossil fuels, vastly expanding our available energy, without being unaware that the byproduct of their combustion – carbon dioxide – would create a climate crisis we would struggle to control. Finally we managed to unlock the enormous energy locked in the heart of matter itself, the atomic nucleus, using it to generate yet more power, but also using it to create tens of thousands of devastating bombs, bringing us to the point today where the world resembles a shed packed to the rafters with fireworks, in a summer getting hotter by the day.

In such a world, the ancient question of how to live meaningfully is more salient and acute than ever. Human meaning is not a universal, unchanging truth, even if philosophers who have contemplated the problem over the centuries have shared some common conclusions. The existential philosophers of the mid-20th century posited that the human condition rested on four fundamental pillars: isolation, freedom, meaninglessness and death. Yet it is clear that these so-called fundamental pillars are not universal at all, but are hallmarks of the modern experience. It is unlikely that ancient humans were tormented by feelings of isolation; they lived in tight-knit communities which were far less lonely than modern societies. Their freedom was limited to such matters as where to live and whom to marry rather than the dizzying panoply of choices faced by the modern person, so it is unlikely they would have understood the existentialists’ anxieties about freedom. They also did not typically suffer from a sense of meaninglessness, since meaning was provided by long-standing belief systems and traditions that seemed beyond questioning. Even mortality did not have the same sting as it does in modern life. People tended to see themselves as part of an unchanging order of life and death in which personal identity was emphasised and hence the destruction of the self less significant and frightening.

In the hundreds of thousands of years of hunter-gatherer existence during which human consciousness evolved, change was slow, meaning was largely fixed and choice was limited. Yet now we face a world in which the conditions which prompted the angst of the existentialists are far more extreme. The scope of the choices we face seems virtually limitless, isolation and loneliness are epidemic and a sense of meaninglessness pervades many people’s lives, dulled only by the anodyne of endless superficial novelty. The brains that we evolve to help us adapt to widely varied environmental conditions are remarkably flexible, but not infinitely so. The sky-high rates of anxiety and depression in young people indicate that we may be approaching the limits of the human tolerance for change.

Our hunger for a sense of purpose in our lives is undiminished. And yet what can we hold onto in such an unstable world? Purpose requires a future we can envisage, yet the horizon in front of us grows ever shorter. Is it any wonder that our young people are so troubled when so little about their future is assured? It is not just climate change that destabilises their sense of a secure future. The collapse of trust in government and traditional media, the viral spread of misinformation and “deep fakes” that undermine the sense that a reliable consensus reality exists, the rise of Artificial Intelligence – which can produce language and art and seem to call into question the very notion of something sacred in the human soul that is beyond mere mechanism – all these things are eroding the fabric of meaning in which human lives are embedded and which prevents them from falling into the void. Lives are doing just that. The fate of polar bears losing the ground they stand on is our fate, too.

It is tempting to imagine meaning in transcendental terms. The Meaning of Life, with capitals. Yet meaning is not transcendent, but immanent. It resides in the web of relations that constitutes the world. When Victor Frankl wrote about his experiences in Auschwitz in Man’s Search For Meaning, the meanings that kept people alive through the horrors of the concentration camp were small, personal dreams, like opening a cake shop, or going back to school and becoming a vet. The humble scale of these dreams should not obscure the profound achievement they represented: to continue to believe in life in the face of overwhelming death and suffering. To dare to make meaning in a world not merely lacking it, but viciously hostile to it.

This, then, is the courage we must take inspiration from, as we go forward into our uncertain individual and collective futures. Heat – energy dissipated into chaos – is the metaphor for our time. As the Great Explosion enters its next, perhaps final, phase, its dissipating energy will melt or burn much of what we have known, including structures of collective meaning on which we have depended. We must counter this rising heat with coolness. We must show stillness in the face of frenzied action, balanced reflection in the face of hysteria, mindful presence in the face of distraction. We must weave small webs of meaning around us, in our families, communities and friendships. There are universal truths behind all of the change: compassion, relationship, kindness, honesty, the wisdom that is anchored in the body. On these things we will always be able to rely.