Chapter 33 Chapter Summary

Peter Singer defends a principle of equal consideration of interests as the correct vision of equality underlying morality. According to this fundamental standard, our basic concern for the needs and interests of other beings should not depend on what they are like. We should instead weigh all similar interests equally, ignoring morally irrelevant characteristics such as the being’s race, gender, or species-membership. To have any interests that can be considered, a being must have a basic capacity to suffer, or sentience.

Singer’s moral principle entails that humans cannot justify ignoring the interest nonhumans have in avoiding suffering. Morality requires that we always give priority to relieving the greater suffering where interests conflict. This has far-reaching consequences for human treatment of animals, qualifying most convention forms of animal use – such as for food or much medical experimentation – indefensible.