In appropriate circumstances we are justified in using humans to achieve goals (or the goal of assisting animals).
Peter SingerPeople tend to care about dogs because they generally have more experience with dogs as companions; but other animals are as capable of suffering as dogs are. Few people feel sympathy for rats. Yet rats are intelligent animals, and there can be no doubt that rats are capable of suffering and do suffer from countless painful experiments performed on them. If the army were to stop experiments on dogs and switch to rats instead, we should not be any less concerned.
Peter SingerAfter 9/11, the American Red Cross received more than half a billion dollars in donations to help the victims of the terrorist attacks. The families of the victims were already well-provided for by various government funds, so Red Cross simply drew a line across lower Manhattan and offered everyone there financial assistance, whether they needed it or not.
Peter SingerIf 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?
Peter SingerThe statement "I am in pain" may be one piece of evidence for the conclusion that the speaker is in pain, but it is not the only possible evidence, and since people sometimes tell lies, not even the best possible evidence. Even if there were stronger grounds for refusing to attribute pain to those who do not have language, the consequences of this refusal might lead us to reject the conclusion. Human infants and young children are unable to use language. Are we to deny that a year-old child can suffer?
Peter SingerWhen 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.
Peter Singer