Whether you are a welfarist seeking to replace battery cages with aviaries, or an abolitionist demanding total veganism, the arc of the moral universe bends toward justice—but it does not bend automatically. It bends because individuals choose to look at the suffering of a sentient being and say, "This is not right."

Humans have higher cognitive capacities (morality, language, abstraction). Therefore, human interests always trump animal interests. Rebuttal: If intelligence is the metric, then human infants and the severely cognitively disabled would also have zero moral value.

, a modern utilitarian, radicalized Bentham in his seminal work, Animal Liberation (1975). Singer argues for the principle of equal consideration of interests . A pig's interest in avoiding pain is identical to a human's interest; therefore, ignoring pig pain because of species is "speciesism"—a prejudice as irrational as racism or sexism. While Singer is often called the father of the animal rights movement, he is technically a welfare reformer who supports incremental improvements while eventually advocating for abolition.