Sentience and moral consideration

 by Sarah Albonesi

family affection


Behaving according to society’s standards of morality is something that we as human beings learn from a young age. Children are often told to treat others as they wish to be treated – or to consider how their actions might benefit or harm others. As humans we grant other humans moral consideration or, in other words, we take our fellow humans beings’ interests into account when interacting with them. At the most basic level, our human interests are to minimize our suffering and unpleasant feelings, and maximize our pleasure and happiness.

While society today generally agrees that we should grant all humans equal moral consideration, it does not agree upon the treatment of nonhuman animals. We frequently use other animals to our advantage when, for instance, we use them for food, clothing, or drug testing. But how do we know whether this behavior is justifiable, and how do we know where to draw the line in using another being to our advantage?

Many philosophers and animal rights activists agree that sentience, or “the capacity for suffering and enjoying things”1 should be the basis for granting an individual moral consideration. Humans and nonhuman animals experience pleasure and pain, and thus share a basic interest in minimizing their suffering and maximizing pleasure. Therefore, if any being has the capacity to suffer, it is essential to avoid causing them unnecessary distress, as to do otherwise would be morally wrong.

If we accept that behaving morally means minimizing suffering, we have a duty as moral beings to grant all sentient individuals moral consideration. Which brings us to the next question: how can we know which beings are sentient?


While most people agree that other human beings are sentient, the consensus on whether other animals are sentient is less definitive. If animals were not sentient, then human beings would have no ethical obligation to grant them moral consideration.

The topic of animal sentience is not a new one. Philosophers and scientists have been discussing this question for hundreds of years, and in 2012 a group of scientists convened at a conference in Cambridge to analyze an abundance of literature regarding animals and sentience. Consciousness is necessary for sentience, as to be sentient means to be capable of having positive or negative experiences, and in order to have any kind of experience, one has to be aware – or conscious – of what is happening. Based on their analysis, the scientists concluded in The Cambridge Declaration on Consciousness:

 Non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors. Consequently, the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.2

Neurological substrates are parts of the central nervous system that give rise to and control specific behaviors and psychological states. This statement means these scientists agree that on a biological level, there is strong evidence that nonhuman animals are conscious beings, and are thus aware of their experiences as sentient beings. Our own experiences with animals also lend support to the idea that they are sentient, as we can often recognize sentient behaviors in them. Most would probably agree, for instance, that the yelp and cowering of a dog signals pain and unease, while the gentle purring of a cat reveals feelings of contentedness.

In addition to physiological and behavioral evidence of animal sentience, examinations of evolutionary theories often conclude that animals are neurologically “wired” the same way as humans, due to their shared evolutionary history.3 Charles Darwin recognized sentience as “an essential feature of evolutionary fitness and believed it to be widespread in the animal world.”4 Darwin felt that the process of natural selection inherently selects for sentient beings. For example, pain can help an animal avoid a disadvantageous experience and pleasure can help reinforce beneficial behavior, and thus sentience would be an advantageous trait.

fawn standing in forest clearing

Physiological, behavioral, and evolutionary evidence aside, some would still argue that we cannot be entirely sure that animals are sentient, as we have no way of knowing what exactly goes on in their minds when they appear to exhibit pain or pleasure. If we believed this to be the case, however, then under the same logic it would also be appropriate to deny other human beings moral consideration, for we cannot know for sure their inner thoughts. As animal rights author Joan Dunayer writes, “I’d rather accord an insentient thing undue respect than slight any being who feels. I’d rather extend moral consideration to something that can’t suffer than fail to extend it to someone who can.”5


It is important to treat animals with respect, as they share with humans an interest in not suffering. Thus because they are sentient, animals  should be respected because they can suffer harm, regardless of whether or not they have the cognitive ability to be self-aware. Furthermore, killing another being without just cause can be seen as immoral, as it deprives that being of future sentient experiences that they could potentially have had.

Extensive discussions about animal sentience like that of The Cambridge Declaration on Consciousness reveal that animals’ interests are being given more credence, at least in the academic world. Hopefully such discussions will lead to a future in which all sentient beings are shown respect and have at least basic legal rights – rights that at a minimum take into account an animal’s interest in life and interest in not suffering.

1 Singer, Peter. “All Animals Are Equal.” In Animal Rights and Human Obligations, edited by Tom Regan and Peter Singer. New Jersey: Englewood Cliffs, 1989.

2 Low P., Panksepp J., Reiss D., Edelman D., Van Swinderen B., Koch C. “The Cambridge Declaration on Consciousness.” (2012).

3 Pollan, Michael. The Omnivore’s Dilemma. London: Penguin Books, 2007.

4 Darwin, Charles. The Descent of Man and Selection in Relation to Sex. London: J Murray, 1871.

5 Dunayer, Joan. Animal Equality: Language and Liberation. Maryland: Ryce Publishing, 2001.