In the time that we are alive on this earth, it could burn in front of us. There could be droughts and famines and wildfires and pandemics of deadly diseases.

But. In the time that we are alive on this earth, it could be transformed into a paradise. The planet could become run entirely on renewable energy, with enough food for everyone, where everything that lives could have all its needs met.

Within our lifetimes, we could once more see a resurgence of fascism, racist nationalism, and global war. We might see once more the increased subjugation of women and the rise of bigoted intolerance.

But. Within our lifetimes, we might be the first generation to witness world peace. We might see a new flourishing of tolerance and inclusion. We might live in a society without inequality, where the rights of all are respected.

Why is it so much easier to imagine disaster than success? Why do we allow our imaginations to deprive us of the possibilities of a better world?

Sure, this world could be horrible. But it could just as easily be wonderful.

What world will our children inherit?

Will it be the burning dystopia that feels so present, or the perfected society that seems so distant?

The Prophet Isaiah was not sure either.

In the build-up to the High Holy Days, we read haftarot from the Prophet Isaiah. The lectionary cycle offered us three readings of warnings and six of comfort. That great leader of ancient Israel struck fear into our hearts with threats of how horrible the future might be. Then he promised us solace with visions of how wonderful life could be. Which should we believe?

In one of his prophecies, Isaiah warns that the coming world will be “a cruel day, with wrath and fierce anger—to make the land desolate and destroy the sinners within it.” He forewarns of unending darkness and exile and terror. He offers no remedy. He tells us that everyone will go to war against each other, that every neighbour will become the other’s oppressor, and nobody will win.

Yet elsewhere, Isaiah envisions a redeemed world, in which the poor see justice, and wolves lie with lambs, and refugees find home, and people beat their swords into ploughshares and no nation goes to war any more.

Isaiah holds two visions in the balance. One of hope and one of fear.

Perhaps we might say that this is the same vision seen from different perspectives: that what would be wondrous for some would seem disastrous for others. That justice for the poor would feel like tragedy to the rich. That the end of war for its victims would be calamity for its profiteers.

But that doesn’t seem plausible. Surely, there will either be outright war or there will be none? Justice may be subjective, but conflict over resources is a fact. Either everyone will have all they need or all humanity will battle fir scraps.

You might say: perhaps these prophecies were given at different points in Isaiah’s life? The historical critics argue that the book of Isaiah in fact had three different authors, all writing in different periods.

But this still doesn’t explain the discrepancy. Within even the same chapter and verse, Isaiah oscillates between dream and nightmare, holding both possibilities in contrast.

The contradiction only exists if you imagine prophets as fore-tellers of a pre-ordained history. The Jewish tradition has tended to see them instead as forth-tellers: bringing God’s word to show what might be possible.

In this week’s haftarah, Isaiah promises both together. Isaiah talks about vengeance and redemption.

Isaiah is showing us the two ways in which humanity might go, and leaving open both options. This world might be brought to its end by disaster. But it could be wonderful too.

The fear of what this world might be can sometimes keep me up at night. I think of unfolding climate catastrophes, with floods and wildfires already engulfing parts of the globe. I see escalating wars between major powers in multiple countries. I hear the rhetoric from political leaders, ramping up racism, xenophobia, sexism and transphobia. And Isaiah’s nightmares do not seem so distant.

But I am trying to rejig my perspective. There is nothing radical or interesting about pessimism. Misery is easy. It is the default for minds accustomed to defeat, prone to anticipate worst case scenarios.

But hope. Hope is harder. Hope demands far more imagination as we expand our horizons of the possible. If we have hope, we cannot give in to how things are. Hope demands of us action.

Recently, I have found reason to hope in fiction. There is a wealth of writing by Jewish eco-futurists, who create worlds set in the not-too-distant future. Instead of the dystopias imagined by 20th Century writers like Orwell and Huxley, they ask a much bolder question: what if we made it right? What would the world look like if, instead of accepting the inevitability of defeat, we projected winning?

A few years ago, TV star and beloved Essex Jew, Simon Amstell, made a film imagining a world fifty years in the future. In it, the whole world is engaged in a truth and reconciliation process, as elders try to explain to the young where they went wrong and how they rebuilt. The new world is idyllic, and all that had to happen, says Amstell, is that everyone stopped eating meat.

The film, called Carnage, is clearly satirical, and takes a self-referential jibe at preachy vegans. But it also posits something intuitively true and beautiful: a better world than this one could be possible with very small changes.

Over the summer, I have been reading the solar-punk fiction of author Sim Kern. Their works imagine alternative worlds to this one. In their major book, ‘Depart Depart’ a dybbuk haunts a Jewish youth as he makes his way through a world ravaged by climate catastrophe. Yet, in more recent works, Kern imagines alternative worlds in which humanity made steps towards addressing these disasters. Imperfect, true, and still full of tension – otherwise there would be no story – but they still pitch another reality. And inhabiting those fictional worlds has helped me realise how real they could be.

Enough with pessimism.

Sure, this world could be horrible. But it could just as easily be wonderful.

Let’s make it so.