‘Animal liberation’ may sound more like a parody of other liberation movements than a serious objective. The idea of ‘the rights of animals’ actually was once used to parody the case for women’s rights. When Mary Wollstonecraft published her Vindication of the Rights of Women in 1792, her views were widely regarded as absurd and, before long, an anonymous publication appeared entitled A Vindication of the Rights of Brutes. The author of this satirical work (now known to have been Thomas Taylor, a distinguished Cambridge philosopher) tried to refute Mary Wollstonecraft’s arguments by showing that they could be carried one stage further. If the argument for equality was sound when applied to women, why should it not be applied to dogs, cats and horses?
When we say that all human beings, whatever their race, creed or sex, are equal, what is it that we are asserting? Like it or not, we must face the fact that humans come in different shapes and sizes; they come with different moral capacities, different intellectual abilities, different amounts of benevolent feeling and sensitivity to the needs of others, different abilities to communicate effectively and different capacities to experience pleasure and pain. In short, if the demand for equality were based on the actual equality of all human beings, we would have to stop demanding equality.
The existence of individual variations that cut across the lines of race or sex, however, provides us with no defence at all against a more sophisticated opponent of equality, one who proposes that, say, the interests of all those with IQ scores below 100 be given less consideration than the interests of those with ratings over 100. Perhaps those scoring below the mark would, in this society, be made the slaves of those scoring higher. Would a hierarchical society of this sort really be so much better than one based on race or sex? I think not. But if we tie the moral principle of equality to the factual equality of the different races or sexes, taken as a whole, our opposition to racism and sexism does not provide us with any basis for objecting to this kind of inegalitarianism.
Fortunately, there is no need to pin the case for equality to one particular outcome of a scientific investigation. There is no logically compelling reason for assuming that a factual difference in ability between two people justifies any difference in the amount of consideration we give to their needs and interests. The principle of the equality of human beings is not a description of an alleged actual equality among humans: it is a prescription of how we should treat human beings.
Jeremy Bentham, the founder of the reforming utilitarian school of moral philosophy, incorporated the essential basis of moral equality into his system of ethics by means of the formula: “Each to count for one and none for more than one.” In other words, the interests of every being affected by an action are to be taken into account and given the same weight as the like interests of any other being. It is an implication of this principle of equality that our concern for others and our readiness to consider their interests ought not to depend on what they are like or on what abilities they may possess. Precisely what our concern or consideration requires us to do may vary according to the characteristics of those affected by what we do: concern for the well-being of children growing up in the US would require that we teach them to read, concern for the well-being of pigs may require no more than that we leave them with other pigs in a place where there is adequate food and room to run freely. But the basic element — the taking into account of the interests of the being, whatever those interests may be — must, according to the principle of equality, be extended to all beings, black or white, masculine or feminine, human or nonhuman.
Thomas Jefferson, who was responsible for writing the principle of the equality of men into the American Declaration of Independence, saw this point. It led him to oppose slavery even though he was unable to free himself fully from his slaveholding background. He wrote in a letter to the author of a book that emphasised the notable intellectual achievements of negroes in order to refute the then common view that they have limited intellectual capacities: “Be assured that no person living wishes more sincerely than I do, to see a complete refutation of the doubts I myself have entertained and expressed on the grade of understanding allotted to them by nature, and to find that they are on a par with ourselves…but whatever be their degree of talent it is no measure of their rights. Because Sir Isaac Newton was superior to others in understanding, he was not therefore lord of the property or person of others.”
(This excerpt is taken from Animal Liberation by Peter Singer)
Peter Singer is an Australian philosopher who specialises in applied ethics and approaches ethical issues from a secular, preference utilitarian perspective