"The utilitarians did assume that man had a special duty to man but the modern view is different -- modern duties must now be equally guided by our relations to animals. The rights of animals is the subject of much controversy, and discussion on the point is undetermined. Some people will eat fish and not meat. There was a man who would eat lobster sauce because it was at the cost of only one life, while he would not eat shrimp sauce because that was a holocaust. In any case it has been well put, that if animals have no rights man has duties to them."
Today you might meet a man who will eat a tomato. The tomato is given by a plant that continues to live after the fruit is plucked. But this man will not eat a carrot because harvesting the taproot is an act of violence destroying the plant. I do not agree with this man, but at least he is arranging an order to his thoughts and he can begin to explain them.