The Expanding Circle

1. Ethics has biological roots in animal altruism

Many non-human animals assist their own kin, or refrain from harming them. In some species this is true of unrelated animals as well.

Evolutionary origins. Ethics didn't emerge suddenly in humans, but has deep evolutionary roots. Kin selection explains why animals help relatives who share their genes. Reciprocal altruism accounts for cooperation between unrelated individuals when there are mutual benefits. Even rudimentary forms of group selection may promote some prosocial behaviors within communities.

Animal examples. Many species exhibit behaviors that resemble human ethics:

• Vampire bats share blood with hungry roostmates
• Vervet monkeys give alarm calls that put themselves at risk
• Dolphins support injured pod members to the surface to breathe
• Wolves and wild dogs bring food back to pack members
• Chimpanzees console victims of aggression

These examples demonstrate that the building blocks of ethics - caring for others, fairness, and cooperation - have biological foundations that predate human morality. Understanding this evolutionary context provides insight into the nature and development of human ethical systems.

2. Reason expands the circle of moral consideration

The process should not stop there. In my earlier book, Animal Liberation, I showed that it is as arbitrary to restrict the principle of equal consideration of interests to our own species as it would be to restrict it to our own race.

Expanding circles. As humans developed the capacity for abstract reasoning, we were able to expand our moral consideration beyond our immediate kin and tribe. This process of expanding the circle of moral concern has been ongoing throughout human history:

• Family/tribe → community → nation → all of humanity
• Humans → some animals → all sentient beings

Rational extension. Reason allows us to recognize that there is no morally relevant difference between ourselves and others that would justify giving their interests less consideration. Just as we expanded ethics beyond family, tribe, race and nation, we can rationally extend moral consideration to other sentient beings capable of suffering. This expansion is not inevitable, but follows logically from impartial moral reasoning.

Practical implications. Expanding our moral circle has major implications for how we treat animals, how we allocate resources globally, and how we consider the interests of future generations. While emotionally challenging, this expansion aligns with rational ethical deliberation and has been a hallmark of moral progress.

3. Sociobiology offers insights but doesn't determine ethics

Understanding how our genes influence us makes it possible for us to challenge that influence.

Biological insights. Sociobiology and evolutionary psychology provide valuable insights into the origins of human moral intuitions and behaviors. Understanding the evolutionary functions of phenomena like kin selection, reciprocal altruism, and in-group favoritism can illuminate why we have certain moral instincts.

Not ethical determinism. However, the fact that we have evolved certain tendencies does not mean we are bound by them or that they are ethically justified. Evolution operates on gene survival, not human wellbeing or impartial moral consideration. We can use reason to critically examine our intuitions and potentially override them.

Key points:

• Biological explanations don't justify behaviors
• "Is" doesn't imply "ought" - we can't derive values from facts alone
• Reason allows us to step back and evaluate our evolved intuitions
• Cultural evolution and rational deliberation can modify/override genetic tendencies
• Understanding our nature allows us to shape it, not submit to it

4. Moral intuitions can be critiqued through rational analysis

Once we understand that they are social creations, normally useful and normally to be obeyed but always ultimately subject to critical scrutiny from the standpoint of impartial concern for all, the need for jesuitical reasoning about moral rules vanishes.

Scrutinizing intuitions. Our moral intuitions and common sense ethical principles are not infallible truths, but products of our evolutionary and cultural history. While often useful, they can and should be subject to rational scrutiny. We can examine their origins, consistency, and consequences.

Rational critique. Some ways to critically analyze moral intuitions:

• Seek logical consistency across similar cases
• Consider impartial impacts on all affected
• Examine historical/cultural contingency of the intuition
• Look for hidden biases or self-serving rationalizations
• Test against fundamental ethical principles (e.g. impartiality)

Balancing act. We shouldn't entirely discard moral intuitions - they often embody useful wisdom. But neither should we treat them as sacrosanct. The goal is to refine our ethical thinking through an ongoing process of intuition and rational reflection, gradually improving our moral frameworks over time.

5. Impartial consideration of interests is the rational basis for ethics

If we were more rational, we would be different: we would use our resources to save as many lives as possible, irrespective of whether we do it by reducing the road toll or by saving specific, identifiable lives.

Impartial consideration. From an objective standpoint, there is no reason to give greater weight to our own interests than to the similar interests of others. Rational ethical deliberation requires adopting an impartial point of view that considers the interests of all affected equally.

Challenging but compelling. This impartial perspective is difficult to fully adopt given our evolved tendencies toward self-interest and in-group favoritism. However, it provides the most logically consistent and justifiable foundation for ethics. Key implications:

• Rejecting ethical egoism and tribalism
• Expanding moral consideration to all sentient beings
• Prioritizing actions with greatest positive impact
• Treating distant strangers on par with those close to us
• Considering long-term and indirect consequences

Practical challenges. While impartial consideration is the ideal, in practice we must balance it against human nature and social realities. An ethical system that completely ignores human tendencies is unlikely to be adopted or followed. The goal is to gradually expand impartial consideration while accounting for human limitations.

6. Ethics involves balancing universal principles and human nature

A rational ethical code must also make use of existing tendencies in human nature. We may attempt to foster tendencies that are desirable from an impartial point of view and to curtail the effects of those that are not; but we cannot pretend that human nature is so fluid that moral educators can make it flow wherever they wish.

Balancing act. Effective ethics must balance universal rational principles with the realities of human nature. While we should strive toward impartial consideration, we must also account for evolved human tendencies and limitations.

Factors to consider:

• Evolved moral intuitions (e.g. care for kin, reciprocity)
• Cognitive biases and limitations
• Emotional motivations and aversions
• Social and cultural influences
• Practical constraints of human societies

Gradual progress. The goal is not to immediately achieve a perfect ethical system, but to make incremental progress. We can:

• Foster and expand positive tendencies (e.g. empathy, fairness)
• Create social structures that align self-interest with ethical behavior
• Develop ethical heuristics and rules that are easy to follow
• Use reason to gradually expand our circle of moral consideration
• Design institutions that account for human nature while promoting ethical outcomes

The most effective approach combines high ethical aspirations with a realistic understanding of human psychology and social dynamics.

7. Moral rules serve important social functions

Hence while the persistence of genuine altruism would be inexplicable if it were based on feeling alone, it becomes much easier to understand if it is not feeling, but reason that is chiefly responsible for it.

Functions of rules. While impartial consideration is the ideal ethical standard, moral rules serve important practical functions in human societies:

• Simplify decision-making in common situations
• Provide clear standards for praise and blame
• Allow for moral education of children
• Foster social cooperation and stability
• Serve as useful heuristics when calculation is difficult
• Help override selfish impulses

Rules and rationality. Moral rules are not foundational ethical truths, but useful tools developed through cultural evolution and rational reflection. They should be subject to ongoing scrutiny and revision based on their consequences.

Balancing rules and consequences. In most cases, following established moral rules leads to good outcomes. However, in rare situations, strictly adhering to rules may produce worse consequences than breaking them. Ethical decision-making involves balancing rule-following with consideration of specific consequences, using reason to navigate difficult cases.

8. Scientific understanding allows us to shape ethical evolution

In the future we will be more aware of the genetic consequences of our practices, and will be able to take deliberate steps to see that our culture not only encourages ethical conduct in the present generation but enhances its prospects of spreading in the next.

Shaping our nature. As we gain a deeper scientific understanding of human nature and the biological basis of ethics, we become better equipped to consciously shape our moral evolution. This involves both cultural and potentially biological interventions.

Potential approaches:

• Design social institutions that foster ethical behavior
• Develop more effective moral education techniques
• Create technologies that expand empathy and moral imagination
• Use genetic knowledge to promote prosocial traits
• Shape cultural narratives and norms to expand moral consideration

Ethical considerations. Any attempt to deliberately shape human moral nature raises profound ethical questions. We must carefully consider the implications and potential unintended consequences of such efforts. The goal should be to expand our capacity for rational moral deliberation and impartial consideration, not to impose a specific moral code.

Ongoing process. Shaping our ethical evolution is not a one-time task, but an ongoing process of reflection, experimentation, and refinement. As our scientific understanding and ethical reasoning improve, we can continually work to create better versions of ourselves and our societies.

Last updated: March 23, 2025