Here is an attack on vegetarianism: Is it better for an animal to exist or not to exist? If it were better for it not to exist, wouldn't it be a virtue sterilising all the animals out there, so that no more come into an unfortunate existence? This would seem absurd. Thus let us conclude that in some cases it is better for an animal to exist. Now the cows, for example, on a farm only exist because someone will eat them later. Assuming also that the cow is kept in humane conditions, and has all the things a cow would want in life, we might conclude that it is better that the cow has been. As this good is wholly dependant on a human being a meat-eater, we conclude that it is virtuous being a meat-eater.