As well as seriously - indeed exhaustively - researching everything that could conceivably go wrong, I think we should also investigate what could go right. The world is racked by suffering. The hedonic treadmill might more aptly be called a dolorous treadmill. Hundreds of millions of people are currently depressed, pain-ridden or both. Hundreds of billions of non-human animals are suffering too. If we weren't so inured to a world of pain and misery, then the biosphere would be reckoned in the throes of a global medical emergency. Thanks to breakthroughs in biotechnology, pain-thresholds, default anxiety levels, hedonic range and hedonic set-points are all now adjustable parameters in human and non-human animals alike. We are living in the final century of life on Earth in which suffering is biologically inevitable. As a society, we need an ethical debate about how much pain and misery we want to preserve and create. How do you break the hedonic treadmill?"