"Whatever anybody says, I feel that the hard problem of consciousness is still very hard, and to try and rest your ethical case on proving something that has baffled people for years seems to me to be not good for animals. Much, much better to say let's go for something tangible, something we can measure. Are the animals healthy, do they have what they want? Then if you can show that, then that's a much, much better basis for making your decisions."