I do not see any reason why animals should be slaughtered to serve as human diet when there are so many substitutes. After all, man can live without meat.
Nothing can be more shocking and horrid than one of our kitchens sprinkled with blood, and abounding with the cries of expiring victims or with the limbs of dead animals scattered or hung up here and there.
For the real difference between humans and other animals is that humans alone have perception of good and evil, just and unjust, etc. It is the sharing of a common view in these matters that makes a household and a state.