Remember that not everyone is as strong as you are. Be mindful of human weakness, and of the fact that it may be more important, in the long run, to get many people taking steps in the right direction than to have fewer achieving the ideal.

My major concern about leaving enhancement to the marketplace is that then the rich will be able to buy themselves genetically superior children and the poor will not - sharpening the class divisions we have now. That problem could be overcome if, genetic enhancement were available to all, subsidized by the state - and that would, over time, have benefits for society as well.

If zoos are like arks, then rare animals are like passengers on a voyage of the damned, never to find a port that will let them dock or a land in which they can live in peace. The real solution, of course, is to preserve the wild nature that created these animals and has the power to sustain them. But if it is really true that we are inevitably moving towards a world in which mountain gorillas can survive only in zoos, then we must ask whether it is really better for them to live in artificial environments of our design than not to be born at all.

By ceasing to rear and kill animals for food, we can make so much extra food available for humans that, properly distributed, it would eliminate starvation and malnutrition from this planet. Animal Liberation is Human Liberation too.

There could conceivably be circumstances in which an experiment on an animal stands to reduce suffering so much that it would be permissible to carry it out even if it involved harm to the animal... [even if] the animal were a human being.

We need to recognise that what really matters isn't buying more and more consumer goods, but family, friends, and knowing that we are doing something worthwhile with our lives. Helping to reduce the appalling consequences of world poverty should be part of that reassessment.

Bush sees the evil as out there in the wider world, residing in people who 'hate freedom'. Look at his immediate response to the pictures of prisoner abuse; this is not what Americans do, these are not our values.