One of the main arguments that I make is that although almost everyone accepts that it is morally wrong to inflict “unnecessary” suffering and death on animals, 99% of the suffering and death that we inflict on animals can be justified only by our pleasure, amusement, or convenience. For example, the best justification that we have for killing the billions of nonhumans that we eat every year is that we enjoy the taste of animal flesh and animal products. This is not an acceptable justification if we take seriously, as we purport to, that it is wrong to inflict unnecessary suffering or death on animals, and it illustrates the confused thinking that I characterize as our “moral schizophrenia” when it comes to nonhumans.
A follow-up question that I often get is: “What about vivisection? Surely that use of animals is not merely for our pleasure, is it?”