With the eventual acceptance of Darwin's theory we reach a modern understanding of nature, one which has since then changed in detail rather than in fundamentals. Only those who prefer religious faith to beliefs based on reasoning and evidence can still maintain that the human species is the special darling of the entire universe, or that other animals were created to provide us with food, or that we have divine authority over them, and divine permission to kill them.

My fear is that that's what's going to happen with robotics and the military. Importantly, this discussion has to involve not just the scientists, but also the political scientists. It's got to be a multidisciplinary discussion. You can't have it be another repeat of what happened with the people working on the atomic bomb.

When fish experience something that would cause other animals physical pain, they behave in ways suggestive of pain, and the change in behaviour may last several hours.

Marx saw that capitalism is a wasteful, irrational system, a system which controls us when we should be controlling it. That insight is still valid; but we can now see that the construction of a free and equal society is a more difficult task than Marx realized.

Human decision-making is complex. On our own, our tendency to yield to short-term temptations, and even to addictions, may be too strong for our rational, long-term planning.

We need to learn how to capture and kill wild fish humanely - or, if that is not possible, to find less cruel and more sustainable alternatives to eating them.

If possessing a higher degree of intelligence does not entitle one human to use another for his or her own ends, how can it entitle humans to exploit non-humans?