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?
Peter SingerThe belief that the animals exist because God created them - and that he created them so we can better meet our needs - is contrary to our scientific understanding of evolution and, of course, to the fossil record, which shows the existence of non-human primates and other animals millions of years before there were any human beings at all.
Peter SingerThe Internet, like the steam engine, is a technological breakthrough that changed the world.
Peter SingerDo business managers have a commitment to anything more than the success of their company and to making money? It would be hard to say that they do. Indeed, many business leaders deny that there is any conflict between self-interest and the interests of all.
Peter SingerShould one break in and free the animals? That is illegal, but the obligation to obey the law is not absolute. It was justifiably broken by those who helped runaway slaves in the American South, to mention only one possible parallel.
Peter SingerIt is an indication of the extent to which people are now isolated from the animals they eat that children brought up on storybooks that lead them to think of a farm as a place where animals wander around freely in idyllic conditions might be able to live out their entire lives without ever being forced to revise this rosy image.
Peter Singer