We ought to consider the interests of animals because they have interests and it is unjustifiable to exclude them from the sphere of moral concern; to make this consideration depend on beneficial consequences for human beings is to accept the implication that the interests of animals do not warrant consideration for their own sakes.

The notion that human life is sacred just because it is human life is medieval.

Surely there will be some nonhuman animals whose lives, by any standards, are more valuable than the lives of some humans.

As for cages themselves, an ordinary citizen who kept dogs in similar conditions for their entire lives would risk prosecution for cruelty. A pig producer who keeps an animal of comparable intelligence in this manner, however, is more likely to be rewarded with a tax concession or, in some countries, a direct government subsidy.

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.

There are some circumstances, for example, where the newborn baby is severely disabled and where the parents think that it's better that child should not live, when killing the newborn baby is not at all wrong ... not like killing the chimpanzee would be.

If animals are no longer quite outside the moral sphere, they are still in a special section near the outer rim. Their interests are allowed to count only when they do not clash with human interests. If there is a clash - even a clash between a lifetime of suffering for a nonhuman animal and the gastronomic preference of a human being - the interests of the nonhuman are disregarded. The moral attitudes of the past are too deeply embedded in our thought and our practices to be upset by a mere change in our knowledge of ourselves and of other animals.