If a being suffers there can be no moral justification for refusing to take that suffering into consideration. No matter what the nature of the being, the principle of equality requires that its suffering be counted equally with the like suffering - insofar as rough comparisons can be made - of any other being. So the limit of sentience is the only defensible boundary of concern for the interests of others. To mark this boundary by some other characteristic like intelligence or rationality would be to mark it in an arbitrary manner. Why not choose some other characteristic, like skin color?

When fish experience something that would cause other animals physical pain, they behave in ways suggestive of pain, and the change in behaviour may last several hours.

Those who purchase meat, fur, and leather have no right to be shielded from the sights and sounds of the slaughterhouses from which these products were produced.

The future of the world depends on how well we meet it.

If we compare a severely defective human infant with a nonhuman animal, a dog or a pig, for example, we will often find the nonhuman to have superior capacities, both actual and potential, for rationality, self-consciousness, communication and anything else that can plausibly be considered morally significant.

Interest in business ethics courses has surged, and student activities at leading business schools are more focused than ever before on making business serve long-term social values.

There is no humane slaughter requirement for wild fish caught and killed at sea, nor, in most places, for farmed fish.