James was a philosopher who specialized in ethics and animal rights. His best-known work is The Elements of Moral Philosophy. James wrote a number of papers defending moral veg*anism. His best known paper on the subject was The Basic Argument for Vegetarianism which argued that it is wrong to cause pain unless there is a good enough reason and that wishing to consume animal products does not come close to justifying the cruelty of animal farming. James argued that the primary reason why cruelty to animals is wrong is because tortured animals suffer, just as tortured humans suffer. James was an atheist and had a naturalistic worldview.
James on Wikipedia