The prospect of immortality has been with humanity for as long as we have understood our own mortality. It has been explored in culture after culture through mysticism, religion and, latterly, medical technology. The prospect of immortality is a uniquely human optimism created in answer to a uniquely human curse – the ability to contemplate our own existence, and its inevitable end.

As our technology improves, the prospect of immortality is beginning to look less and less ludicrous. Perhaps not true immortality any time soon, but the idea that in the mid-to-distant future we might be able to prevent ageing and eradicate most diseases is at least conceivable. But before we allow ourselves to become hopeful, it is important to give serious philosophical thought to the pros and cons of living indefinitely. Are there any convincing objections to the prospect of immortality?