When children see animals in a circus, they learn that animals exist for our amusement. Quite apart from the cruelty involved in training and confining these animals, the whole idea that we should enjoy the humiliating spectacle of an elephant or lion made to perform circus tricks shows a lack of respect for the animals as individuals.

Killing a defective infant is not morally equivalent to killing a person. Sometimes it is not wrong at all.

Habits of thought lead us to brush aside descriptions of cruelty to animals as emotional, for "animal-lovers only"; or if not that, then anyway the problem is so trivial in comparison to the problems of human beings that no sensible person could give it time and attention. This too is a prejudice - for how can one know that a problem is trivial until one has taken the time to examine its extent?

Take for example providing a guide dog for a blind person. That's a good thing to do, right? All right. It is a good thing to do. But you have to think what else you could do with the resources. It costs about $40,000 to train a guide dog and train the recipient so that the guide dog can be an effective help to a blind person. It costs somewhere between 20 and $50 to cure a blind person in a developing country if they have trachoma. So you do the sums, and you could provide one guide dog for one blind American or you could cure between 400 and 2,000 people of blindness.

We should aim for our children to be good people, and to live ethical lives that manifest concern for others as well as for themselves.

If we are concerned about the exploitation of human workers in countries with low standards of worker protection, we should also be concerned about the treatment of even more defenceless non-human animals.

To protest about bullfighting in Spain, the eating of dogs in South Korea, or the slaughter of baby seals in Canada, while continuing to eat eggs from hens who have spent their lives crammed into cages, or veal from calves who have been deprived of their mothers, their proper diet, and the freedom to lie down with their legs extended, is like denouncing apertheid in South Africa while asking your neighbors not to sell their houses to blacks.