Singer's "Animal Liberation"

In “Animal Liberation,” Peter Singer argues that human exploitation of non-human species is a “continuing moral outrage,” because there is no justification for treating the interest of any being which has interests as less morally important than the like interest of a human being. Justice is a matter of treating equals equally, but not all inequalities matter for the relevant conception of equal treatment: for example, we should not think that minor genetic differences between races or sexes should result in different social, civil, or political rights even if those differences were found to correlate to small but measurable differences in average IQ. In short, Singer argues that it would be objectionably speciesist to believe “that we are entitled to treat members of other species in a way which it would be wrong to treat members of our own species,” because the relevant capacity for equal treatment is the capacity to suffer, and the members of many, many animal species have that capacity. He then draws out the implications of this view for current practice: vivisection, animal research, and factory farming are all morally impermissible because they brutally harm animals—animals who, by virtue of their capacity to suffer as we do, are thereby also entitled to the same level of respect and compassion.