Many civilisations have myths about the elixir of life: a magical substance that can make those who drink it immortal. The first Chinese emperor, Qin Shi Huang, supposedly sent an expedition out to find it. Mediaeval Europeans believed they could create the elixir through alchemyA science used in the Middle Ages. The aim was to turn things into gold. .

Today, we have given up the search for the elixir of life. But we do have the next best thing: medicines that can prolong our lives to a point our ancestors could never have hoped for.

This week saw the arrival of a new drug that many scientists are calling a turning point in the struggle against Alzheimer's, the most common kind of dementiaA syndrome associated with memory loss and other declining brain functions. .

Alzheimer's affects the brain, especially memory. It causes great distress to sufferers and their families and is always fatal.

We still have no way of stopping or reversing Alzheimer's once it has set in. But the new medicine, called donanemab, has been proved to slow it down.

But some say we have become too obsessed with trying to cure all the world's diseases.

Diseases, they say, are actually very useful things. Researchers have found that they play a vital role in our ecosystems. When a single species becomes too abundant, pathogensAn organism that causes disease to its host. reduce their number, restoring balance.

Some argue that disease is a great leveller. The older generation is currently the richest. The baby boomerA person born just after World War Two. There was an increase in the birth rate at the time. generation owns more than half of all the UK's wealth.¹ If we cured all diseases, older people would live much longer and hoard even more.

But others are not convinced. They point out that disease is very expensive. In total, the world spends $9 trillion each year on healthcare.² We could save this money if we cure all disease.

And disease hardly redistributes wealth, they say. In reality, poor people are worse affected than rich people by diseases.

Yes: Human beings have always dreamt of doing away with disease. This new miracle drug is proof there is nothing we cannot accomplish. Even immortality could be just around the corner.

No: The idea of a wonder cure is nothing but hype. We can never get rid of all the world's millions of diseases, nor should we want to. No good will come of trying to separate ourselves from our nature.

Or... We should not aim to get rid of death: human beings have to die. But we should let them do it on their own terms, instead of letting disease do it at random, and often with great suffering.