Australian-born ethicist Peter Singer (1946 -), dubbed by The New Yorker as "The most influential living philosopher," has done much to ensure the ethical treatment of animals. His book Animal Liberation is widely considered to be the founding philosophy of the animal liberation movement. Singer is a utilitarian and values rational consistency in his ethical position, and this stance leads to many controversial moral views. An internet search will acquaint the student with Singer's philosophy.

According to Singer, sex with animals can result in "mutually satisfying activities" and would therefore be morally justified. Exploitation, harm, or abuse of animals during such activity would not be morally justified. Does he make a moral case for zoophilia? Or, has a line been crossed? Would Singer's arguments also justify sexual relations with children? Are there limits to a strictly utilitarian view of sexual relations? Would a rights-based approach give the same justification? How much can we love animals?"