When most people eat animal flesh they do so in order to receive two goods; pleasure and nutrition. Pleasure is in some sense a luxury, though it should not be forfeited for without good reason. When there are overriding reasons not to engage in pleasurable activities, the pleasurable activities should be forgone. On the other hand nutrition is quite necessary; one needs a good source of nutrition to keep alive and well. Since vegetarian diet is a good source of nutrition for the majority of human animals, it is simply not necessary to kill a nonhuman animal and eat it for nutritional purposes. These considerations may seem like truisms, yet it is important to note that if meat eating is to be justified it must be in terms of the pleasures received from it. The good from killing an animal and eating it is the pleasure received from a few meals (along with the nutrition of course). Yet consider the good obtained from not killing the animal, the animal receives pleasure from the rest of meals it devours in its life and the would-be human carnivores still receive at least minimal pleasure from eating vegetarian. Killing an animal and eating it deprives that animal of pleasure unnecessarily hence it is immoral. Here is the basic argument:
- A world with more pleasure is necessarily a better world than a world with less pleasure
- A moral person endeavors to make the world a better place, and works even more so to not make the world a worse place
- Animals enjoy their meals, (they have the capacity for pleasurable experiences)
- Animals are killed unnecessarily
- An animal will have many more meals if it is not killed; opposed to the human who will only have a few meals if it is killed and eaten
- Thus the world where the animal is allowed to live is a more pleasurable world than the world where animals are killed and eaten unnecessarily.
- Thus a moral person will endeavor to create that world.
Premise 3 needs to be supported. It is a reasonable to believe that animals have the capacity for pleasure, because of the neurological similarities between animals and humans, positive behavior responses, and the evolutionary role of pleasure. Both human and nonhuman animal brains contain dopamine, a chemical which rewards the brain after eating. Rewards for good behavior, behavior which will increase chances of survival is quintessential to the functioning of evolution. Given these three factors it would seem unreasonable to suppose that animals do not have pleasurable experiences.
With premise 3 supported, the argument is successful. It is quite simple, yet I believe quite convincing. Killing an animal and eating it deprives that animal of pleasure unnecessarily. Unless sustainable objections can be made against vegetarianism or this argument then one ought to be vegetarian (or vegan). I don’t envisage any objections of that sort. (In other words I will comment on objections at a later point in time)