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

History is not going to look kindly on us if we just keep our head in the sand on armed autonomous robotics issue because it sounds too science fiction.

If penicillin had been judged by its toxicity to guinea pigs, it might never have been used by man.

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?

We are not especially 'interested in' animals. Neither of us had ever been inordinately fond of dogs, cats, or horses in the way that many people are. We didn't 'love' animals.

Even people who are aware that the traditional family farm has been taken over by big business interests, and that some questionable experiments go on in laboratories, cling to a vague belief that conditions cannot be too bad, or else the government or the animal welfare societies would have done something about it.

Unfortunately for ethical egoism, the claim that we will all be better off if every one of us does what is in his or her own interest is incorrect. This is shown by what are known as "prisoner's dilemma" situations, which are playing an increasingly important role in discussions of ethical theory... At least on the collective level, therefore, egoism is self-defeating - a conclusion well brought out by Parfit in his aforementioned Reasons and Persons.