Further, the compartment was blocked with a glass plate and the dogs would smash into the glass. The use of animals for food is probably the oldest and the most widespread form of animal use. Bentham is not saying that those who try to mark 'the insuperable line' that determines whether the interests of a being should be considered happen to have selected the wrong characteristic.
To avoid speciesism we must stop these practices. Pecorino We are now considering only the application of the principle of equal consideration of interests.
The case against using animals for food is at its strongest when animals are made to lead miserable lives so that their flesh can be made available to humans at the lowest possible cost. The slippery slope argument is important in some contexts, but it cannot bear too much weight.