Ethical theories and nonhuman animals

Ethical theories and nonhuman animals

We all act in certain ways. Our acts and the ultimate reasons behind them are what constitute our morals. We act according to goals we intend to reach, such as reducing suffering, increasing happiness (ours and that of others), reducing harm suffered by sentient beings, and benefiting the worst-off. Some people also act according to certain norms, such as keeping promises or telling the truth.

Ethics is a critical reflection on how we should act and why. Animal ethics is the field of ethics that deals with how and why we should take nonhuman animals into account in our moral decisions.

Different ethical theories disagree about how we should act in many situations. For example, according to some views it is always wrong to tell a lie, regardless of the consequences. According to others, whether or not we should lie depends on the situation and what the outcome would be for those affected by the lie.

Despite their many differences, the most widely accepted ethical theories all support a defense of the moral consideration of nonhuman animals and the rejection of speciesism (discrimination against nonhuman animals). The arguments of each theory are different, since each theory has its own framework of reasons for why we should act in some ways and not others. However, the different arguments used in all these theories arrive at the same conclusion: that we should take the interests of all sentient beings into account. This is because they apply universally, and not just to some particular theory.

Learn more about how the moral consideration of nonhuman animals can be defended according to the major ethical theories in the texts below:




Suffering-focused ethics

Negative consequentialism

Rights theories


Virtue ethics and care ethics

Discourse ethics

In different societies and social groups there are usually different assumptions about how humans should live. Accordingly, moralities vary according to place and time.

We may simply accept the way we’ve been taught to live since birth; however, many people question these assumptions over time, and consider the morals they have been taught. Even those who do not have such a critical attitude may eventually find their different moral assumptions to be in conflict, and have to face, at some points in their lives, situations in which they have to decide what to do when their moral assumptions conflict. For example, someone may believe that we should never break a promise and that we should always try to help the needy. If a situation arises in which they have to decide between helping the needy or keeping a promise, then they would face a moral dilemma.

When we think through such dilemmas we are reflecting on our moral situation, and we call this reflection “ethics”. Ethics is different from morals. Morals are actions and the reasons behind them. Ethics is the critical reflection on morals. The aim of ethical thinking is to detect contradictions among different moral claims and to consider what to do about them. For example, if we claim that we should respect all those who can suffer and that we can exploit women or nonhuman animals, then that is a contradiction we must try to resolve.

General ethical approaches

Ethics is the analysis of the reasons why we should act in certain ways rather than others. There are many different ethical theories, which differ according to the way in which they require us to act and in the arguments that support them. The most widely accepted ethical theories fall within some of the groups below:


Consequentialist theories state that there are things, actions, states of affairs, etc. that are good, or better than others, and claim that we should act in ways such that these things occur. According to consequentialist views, we should act to bring about better situations. For instance, we may think that what is best is a world in which there is as much happiness and equality as possible. Then we would think that the best way to act is to bring about a world with more happiness and equality. Utilitarianism and negative consequentialism are types of consequentialism.


Deontology claims that there are certain actions that are forbidden and others that are required, no matter what consequences follow from them. For example, suppose that by telling one lie we could ensure that no more lies would ever be told. According to deontology, the first lie still should not be told because lying is forbidden.

There are many different forms of deontological views. Some of these concern actions that we should not carry out. Some claim that we should not kill, others that we should not lie, others that we should not break promises, etc. Others are about actions we should carry out. Some claim that we should help others to make their lives better, that we should strive to protect others from suffering harms, or that we should follow rules of etiquette, etc.

Rights theories are typically deontological views, although some versions are consequentialist. Prioritarianism is typically a consequentialist view, though some versions can be deontological. Egalitarianism can be either consequentialist or deontological.

Character ethics

Character-based ethics supposes that what matters most is not the concrete actions we should or shouldn’t carry out, but, rather, developing what we consider a sound moral character. These views claim that in order to know how to act we should ask ourselves how a moral agent with a good character would act rather than acting in accordance with the best outcome for the situation, or considering moral requirements or prohibitions. In practice, though, this view may prescribe the same courses of action as either of the previous two theories do.

Virtue ethics and care ethics are examples of character ethics. Finally, suffering-focused ethics are compatible with consequentialism, deontology or character-based ethics.

Conflicts between and within different ethical theories

What is right according to one theory may be wrong according to another. Some theories may themselves be internally inconsistent, and thus have to be rejected. An example of such inconsistency is a theory that takes into account all humans but not those without complex cognitive capacities.

Even among consistent ethical theories we find disagreements. Different people have different views. There may be no way to solve the disagreement among them in definite terms. But an ethical theory can still be useful in helping us decide how to act in most situations.

Although people have different intuitions and preferences for ethical views, one feature is that the most widely accepted theories support the moral consideration of nonhuman animals.