Quote from : Dominion: The Power of Man, the Suffering of Animals, and the Call to Mercy Book

Though reason must guide us in laying down standards and laws regarding animals, and in examining the arguments of those who reject such standards, it is usually best in any moral inquiry to start with the original motivation, which in the case of animals we may without embarrassment call love. Human beings love animals as only the higher love the lower, the knowing love the innocent, and the strong love the vulnerable. When we wince at the suffering of animals, that feeling speaks well of us even when we ignore it, and those who dismiss love for our fellow creatures as mere sentimentality overlook a good and important part of our humanity.