I think it's something that dawns on you with the most ghastly, inexorable sense. I didn't suddenly wake up in my pram one day and say 'Yippee, I - ', you know. But I think it just dawns on you, you know, slowly, that people are interested in one, and slowly you get the idea that you have a certain duty and responsibility.

Fast food may appear to be cheap food and, in the literal sense it often is, but that is because huge social and environmental costs are being excluded from the calculations. Any analysis of the real cost would have to look at such things as the rise in food-borne illnesses, the advent of new pathogens, antibiotic resistance from the overuse of drugs in animal feed, extensive water pollution from intensive agricultural systems and many other factors. These costs are not reflected in the price of fast food.

The world's forests need to be seen for what they are - giant global utilities, providing essential public services to humanity on a vast scale. They store carbon, which is lost to the atmosphere when they burn, increasing global warming. The life they support cleans the atmosphere of pollutants and feeds it with moisture. They act as a natural thermostat, helping to regulate our climate and sustain the lives of 1.4 billion of the poorest people on this Earth.

Humility is to make a right estimate of one's self. It is no humility for a man to think less of himself than he ought, though it might rather puzzle him to do that.

When people are uncertain about what is right and what is wrong, and anxious about being considered old-fashioned, it seems to be worse than folly that Christians are still arguing about doctrinal matters which can only bring needless distress to a number of people.

Father told me that if I ever met a lady in a dress like yours, I must look her straight in the eyes.

If you think about the impact of climate change, [it should be how] a doctor would deal with the problem. A scientific hypothesis is tested to absolute destruction, but medicine can't wait. If a doctor sees a child with a fever, he can't wait for [endless] tests. He has to act on what is there. The risk of delay is so enormous that we can't wait until we are absolutely sure the patient is dying.