Peter Allison said this quote

She asked another question: What does it matter if the rhinos die out? Is it really important that they are saved?This would normally have riled me... but I had come to think of her as Dr. Spock from Star Trek - an emotionless, purely logical creature, at least with regards to her feelings for animals. Like Spock, though, I knew there were one or two things that stirred her, so I gave an honest reply.... to be honest, it doesn't matter. No economy will suffer, nobody will go hungry, no diseases will be spawned. Yet there will never be a way to place a value on what we have lost. Future children will see rhinos only in books and wonder how we let them go so easily. It would be like lighting a fire in the Louvre and watching the Mona Lisa burn. Most people would think 'What a pity' and leave it at that while only a few wept