In Gaia and God, Rosemary Ruether talks about animal rights. On page 196, Ruether says something about Rene Descartes that caught my eye, since I like animals:
"Descartes reduced animals to 'automata,' which appear to be lifelike but are actually moved by mechanical power, like clocks. This view also was used to justify vivisectional experimentation on animals, by assuring the experimenters that the cries and writhings of animals were mechanical reflexes. Since animals lack 'soul,' they cannot possibly 'feel.' In effect, Descartes severed the continuum between organic body, life, sensibility, and thought. This continuum was split into thought, found in God and the human mind, and dead matter in motion."
The words "cries" and "writhings" in that passage are quite powerful, since "cries" and "writhings" are the things that indicate that animals feel---the very things that should elicit our compassion as human beings.
Ruether talks about extreme animal rights activists. But she herself is not a preservationist. She observes in nature that there is a balance that consists of predators and prey. On page 301, she mentions an article that "showed how sentimental attachment to elephants resulted in a proliferation of these animals that virtually destroyed the huge area of the Kenyan Wildlife Park as a life-bearing habitat for elephants and any other life." She does recommend that people eat lower on the food chain, on account of the cruelty to animals that occurs through factory farming (page 223), as well as the land in Third World countries that is cleared to produce meat for the "United States and local elites, reducing the land for grain crops that feed the poor" (page 285). But she does not think that vegetarianism should be an absolute rule for everyone, for there are natural methods of raising animals for food, plus, for Third World peasants, "the occasional chicken or pig" may be an "indispensable part of an otherwise very limited diet" (page 225).
On page 226, Ruether says what she does advocate:
"The rights of sentient animals to be free of excessive pain and to enjoy a modicum of qualitative life, even if their final fate is the human dinner table; the need for 'wilderness' habitats to have a balance of predator and prey, if some animals are not to destroy their own carrying capacity; the need to preserve biotic diversity and prevent rapid extinction of species---all these are values that need to be defended."
Back when I was reading some introductory books about Judaism in college, I appreciated Judaism's compassion for animals---how Jews slaughter animals for food in a manner that causes the animals no pain. Yes, we can eat animals, but we should be compassionate for all sentient life.
But are there times when the well-being of humans may necessitate the pain of animals? I remember an episode of Quantum Leap in the 1990's, entitled "The Wrong Stuff." In that episode, Sam quantum lept into a monkey, and Sam needed to get the monkey into the space program so that his head wouldn't be smashed in a helmet testing experiment. One of the scientists was very protective of the monkeys, whereas another scientist gave an impassioned speech about how the helmet tests save pilots' lives. Some wonder if there are other ways for us to accomplish our goals, or if our advanced technology is worth the pain that animals experience.