Skip to content

Turning 40: Animal Liberation in perspective

Practical ethics should be all about really having an impact on the world. This requires, among other things, working on the topic regarding which we are expected to produce the most good. Plausibly, these are topics that have been traditionally neglected or at least that remain under-researched. These are also moral issues that may seriously affect a great number of individuals.

This year marks the 40th anniversary of the publication of Animal Liberation, in 1975. With it Australian philosopher Peter Singer initiated one of the highest impact careers in philosophy of the last century. It is not surprising that in 2005, Time magazine included him among the list of the 100 most influential people. It is remarkable, though, that the growing respect for Peter Singer has not been accompanied by a similar change of attitude regarding animal ethics —precisely the field in which he is recognised to have made a greater difference.

Animal Liberation boosted the contemporary academic debate on animal ethics and inspired the work of many other philosophers. This book contributed significantly to the growth of the movement for the equal consideration of nonhuman animals. It has influenced countless individuals to adopt veganism and to become activists in defence of animals. Even though the end of speciesist attitudes lies in the far future, very few other moral aims can produce a similar or greater good. Given the importance of the book, it is worth reviewing, on occasion of its anniversary, the position that Singer defended in it as well as some of the controversies it raises and issues it leaves open.

Animal Liberation is a non-academic book targeted at the general public. It is written by a  philosopher with a particular moral outlook —utilitarianism— and with particular views about specific moral problems. Its aim is clear: denouncing speciesism and abandoning the consumption of animals, especially for food. Its method is effective: using arguments that most people already accept without having to commit to some of the author’s most controversial views.

The book’s main thesis is that the interests of all those who can suffer and enjoy should be equally considered. This is derived from the combination of two premises many of us find uncontroversial. Firstly, the widely shared and robust intuition about the equal consideration of all human beings and, secondly, the need for consistency in moral reasoning. The acceptance of the first idea is what leads us to reject assigning different weight to the interests of some individuals based, for example, in certain biological attributes such as sex or skin colour. Analogously, inasmuch as species membership does not condition the weight of an individual’s interests, it should also be rejected as a morally relevant attribute. The unequal consideration of similar interests based on the species of individuals should thus, for the sake of consistency, be abandoned as another form of discrimination (speciesism).

Furthermore, the argument from ‘species overlap’ shows us that any attempt to draw a moral line between human and nonhuman animals will ultimately fail. No matter what attribute one may appeal to, some human beings will lack it and/or some nonhumans will possess it. Of course, it is implausible to derive from this that those humans who lack the selected attribute should be denied moral consideration. Instead, Singer claims, equality in the consideration of interests should be extended beyond the human species to cover all sentient individuals. Since suffering has negative value, we have reasons to prevent it or alleviate it whenever we can, no matter the species of the individual who experiences it.

Perhaps the most controversial aspect in Singer’s view has been the one related to the ethics of killing animals. As it is suggested in Animal Liberation, and later clearly stated in Practical Ethics (2011), Singer believed at the time that only those individuals with a capacity to see themselves as extended over time can have an interest in continuing to live and thus be harmed by dying. Singer took this to follow from his version of preference utilitarianism, according to which death can only be bad if it frustrates a desire in being alive. Given that most nonhuman animals lack the necessary psychological capacities to harbour the relevant desire, this would entail that death cannot harm them. Thus, their interests would give us no reasons against killing them. If those reasons exist they will be given by other considerations, such as the maximisation of net positive experiences.

However, recently, Singer changed his view about the badness of death, prompted by his transition from preference utilitarianism to hedonistic utilitarianism. In The Point of View of the Universe (Lazari-Radek & Singer 2014), he acknowledges that all sentient beings with a life worth living (understood in hedonistic terms as containing a surplus of positive experiences) are harmed by death, since they are thereby deprived of the benefits they would have otherwise enjoyed.

Nevertheless, Peter Singer has not yet completely fleshed out his new account of the badness of death and the wrongness of killing animals. In fact, in a recent talk, he identified this topic as one of three most important open questions in animal ethics. The other two are, according to Singer, (a) the problem of performing interspecies comparisons of well-being and (b) whether we have reasons to intervene in nature to prevent or alleviate wild animal suffering.

Even if we disagree with Singer’s general utilitarian approach (e.g., if one believes, as I do, that equality matters as such) we must concede that very few philosophers can be said to have had an equally high impact. Forty years ago, Peter Singer realised that working on animal ethics was one of the most effective ways of doing good. Given the work that needs to be done and the billions that can benefit from it (considering both animals under human control and those living in the wild), that is still true today.


Singer, P. (2004). Animal Liberation, 4th Edition. New York: HarperCollins.

Singer, P. (2011). Practical Ethics, 3rd Edition. Cambridge: Cambridge University Press.

Lazari-Radek, K. & Singer, P. (2014). The Point of View of the Universe. Sidgwick and Contemporary Ethics. Oxford: Oxford University Press.

Share on

7 Comment on this post

  1. I disagree that little or nothing has changed in real-world animal ethics. I am most familiar with events in the U.S. Bowing to public pressure, major food producers have begun phasing out pregnant pig gestation crates and battery chicken cages, two of the most egregious examples of the torture of animals in factory farming. Other practices are being changed slowly also. Several of the most infamous primate experimentation laboratories have been closed and their residents relocated to sanctuaries. Ringling Bros. circus has just announced the phasing out of elephants from its shows. This public pressure has been built through tireless campaigns by animal rights organizations such as People for the Ethical Treatment of Animals, Mercy for Animals and the Humane Society of the U.S, among many others. The European Union took the lead in some of these changes and provided a pathway for the U.S. There is no doubt that much remains to be done across a whole spectrum of animal abuses, including in many countries where animal rights is a virtually unrecognized term, but the developments I point in Europe and the U.S. to seemed inconceivable only a few years ago, and point to a widening change in public opinion on how animals may be treated. Some of the impetus for these developments may be credited to Prof. Singer’s book Animal Liberation.

  2. Hi Charles!

    Thanks for your comment. Not sure if I understand the disagreement, though. My point was that there is a huge gap between the respect for Peter Singer and the respect for Animal Ethics as a philosophical discipline inside academia. And this strikes me as curious because, as I say in the post, respect for Peter Singer is mostly due to his work in Animal Ethics. This is, of course, perfectly compatible with all the legislative changes you mentioned.

  3. Oh, I didn’t realize you were talking of only academia, which must be trailing behind the wider society that is beginning to change somewhat. I am sorry to hear that animal rights haven’t made headway in philosophy departments. I do remember, however, reading about academic efforts to make the case for granting primates rights a few years ago. Perhaps it was by academic legal faculty rather than philosophy departments. Did that fizzle out?

    1. “My point was that there is a huge gap between the respect for Peter Singer and the respect for Animal Ethics as a philosophical discipline inside academia.”

      This doesn’t seem very surprising to me. There are lots of cases where the leader of a pack might be regarded very highly, but some of the folks who are related (thematically, perhaps) are regarded more sceptically. Nietzsche, for instance, or Robert Nozick.

      In Singer’s case, there are a whole bunch of areas that his sort of utilitarianism all the way down approach has influenced. eg the (noisy) effective altruists around here seem to have a lot of love for the guy… (ie they might disagree with you about your argument that Singer’s greatest contribution has been Animal Liberation). My guess is that – as with Nozick – a lot of folks have respect for Singer, and find his arguments significant. But in both cases some of the folks who claim to be influenced by the Great Man come across to the person on the Headington omnibus as crazy, which rather spends down whatever capital the sub-field of animal rights or libertarianism might have otherwise accumulated.

  4. Thanks, Dave!

    I believe that since effective altruists identify animal suffering as one of the most important current moral issues, they would be ready to accept my argument on Singer’s impact. As Will Crouch puts it:

    “Why? A staggering 50 billion non-human land animals are killed every year for food. A large proportion of those animals are factory farmed, living in extreme suffering. There are compelling arguments to the conclusion that we should treat non-human animal suffering as being on a par, morally, as human animal suffering. If this were true, then the annual animal suffering caused by humans could easily outweigh all human suffering.”



  5. How do you who are animal rights (or perhaps you would prefer to say animal liberation) philosophers, rate animal political and social activism? Do you feel it is important to join and participate in activism with on-the-ground organizations that seek to achieve change, say with factory farming, or is it enough for you to try to bring about changed views in academia? How much, in this area, will philosophy influence societal change? I think this is a good topic particularly for a blog with ‘practical ethics’ in its title.

  6. Indeed, Charles. Thanks for the suggestion.

    You can find answers to many of your concerns regarding impact and methodology at animalcharityevaluators.

Comments are closed.