“I happened to find the Laudato si’ on Twitter and I thought its being a Catholic text would not have been a problem, because students are free to have a critical attitude. I want to teach the students who attend my courses to think with their own heads”: Paul Nathanail is professor of geology at Nottingham University and, at the environmental management PhD course where he teaches, he handed out the Pope’s encyclical as a textbook. Mr Nathanail – SIR asked him –, why did you decide to use Pope Francis’s encyclical? “People are increasingly aware that science knows what problems are and has the technology to address them, but it is very important to encourage people to change their behaviour, and this is something that engineers and scientists cannot do”, Mr Nathanail answered. “What’s interesting for us – he points out, in the interview – is that such an important spiritual authority as the Pope is, who leads millions of people, chose to use his authority to encourage a certain style of environmental behaviour. It’s not a politician, a scientist, an engineer or an economist telling us what we should do, it’s a spiritual leader encouraging his devotees to treat the environment well”.