The demolition of the Jungle camp in Calais this week has highlighted a moral paradox at the heart of the debate about migration. The media are full of heart-rending stories of the suffering, endurance and hope of individual migrants - each one of them a compelling cry for our help and understanding. Yet, despite our growing collective knowledge of the plight of migrants, our attitude to migration seems to be hardening. Why? In many other areas of our society the opposite is true. Take, for example, the case of mental health. As more people overcome stigma to talk about it, we know more about its impact, our empathy with suffers has increased and people are now being treated more humanely. It's a virtuous circle that doesn't seem to work for migrants. Is this a failure of our moral imagination? How can we, at the same time, feel moved by the plight of one refugee but indifferent to the plight of thousands of refugees? Should we be trying to turn what we can see to be right in individual cases into general moral principles to be applied across the board? Or is it sometimes legitimate and desirable to reduce morality to numbers? What it may be rational to do for one individual, it may be irrational to do for thousands. When the German Chancellor Angela Merkel reacted, like most of us, with horror to the terrible picture of the body of a drowned toddler being carried from a Greek beach, she agreed to take in hundreds of thousands of Syrian asylum seekers. Now many in Germany and across Europe are questioning whether that was the right and moral thing to do as countries struggle to accommodate the new arrivals. Was that a triumph of moral imagination or the worst kind of emotionally driven gesture politics? Moral imagination and migration. Witnesses are Matthew Parris