Animal Liberation: A New Ethics for Our Treatment of Animals is a book by renowned Australian philosopher Peter Singer. Published in 1975 and re-released most recently in 2009, with an additional preface by the author, the book is widely recognized as a foundational text within the animal liberation movement. Singer tries to persuade the reader of his or her own implicit “speciesism,” a term he popularized, and he argues that the discrimination against other species simply because they are not human is unethical. Singer uses the feminist and civil rights movements as comparisons to the fight against speciesism in order to prove the existence of this prejudice. 

After establishing the definition of speciesism, Singer proceeds to explain and dismantle the ideology of equality. He asserts that equality is an egalitarian type of consideration in spite of difference. Singer holds that all beings capable of suffering, as animals are, are worthy of equal consideration. Thus, animals should be given rights suited for their level of sentience. Animals would not be given the right to vote, for example, but should be given ample food, water, and space to roam without fear of slaughter. 

To inform his readers about the laboratory experiments conducted on animals in the United States, Singer lists the starvation, electric shocks, and psychological and physical torture animals receive throughout numerous experiments. He also provides statistics and numbers directly from these research reports in an attempt to thwart the accusation of bias. The conclusions of these experiments are often inconclusive or inapplicable to humans, and call for further testing. Singer attests that these experiments hold no purpose and are a way for scientists to attain funding. Singer does, however, state that there are situations where animal testing might be required. He pushes for the establishment of a board, including members of the scientific and animal welfare community, where these situations can be determined and experiments can be vetted.

Singer then addresses the state of factory farming. He estimates that over 100 million cows, pigs, and sheep are raised for slaughter in the United States alone, while over 5 billion poultry are killed for the dinner table. Farming as the world once knew it has long been over, replaced with “factory farming” that emphasizes efficiency and cost efficacy above all else. Singer describes the starvation, overcrowding, torturous procedures, and eventual slaughter in great detail. He dispels the illusion of the happy, idyllic farm that most individuals have.

After informing his readers about the realities of animal experimentation and “factory farming,” Singer provides them with a solution: vegetarianism or veganism. Singer dispels several myths about vegetarianism, addressing common concerns such as protein and iron intake, vitamin B12 deficiency, and possible health risks. Environmentalism is also a reason to become vegetarian because of the fossil fuel, water, and even food waste spent on raising animals for slaughter. 

Singer then discusses the roots of “speciesism” in the West, specifically in Western religion and theology. The elevation of the human soul over those of other creatures is a central tenet in Christianity; Singer analyzes the writing of numerous religious figures to examine the slow evolution of this attitude into anthropocentrism and eventually “speciesism.” Finally, Singer analyzes the state of “speciesism” in the 1970s and disputes several claims that “human problems come first” (213). He goes into further detail about how the animal rights movement and its leaders have often had historical connections to feminist and anti-racist movements.

Singer goes on to encourage individuals to speak out about the reasons behind their boycott of the meat industry. He also challenges the media to inform the public about animal rights and issues a call to action for the public to reform the utilitarian view it has about animals. Singer concludes the book by entreating his readers to recognize that speciesism and animal cruelty are indefensible and to put into practice “our capacity for genuine altruism” (236).