One of the philosophers skeptical of the idea of non-human animals having self-consciousness is Stuart Hampshire of Oxford. "It would be senseless to attribute to an animal a memory that distinguished the order of events in the past, and it would be senseless to attribute to it an expectation of events in the future. It does not have the concepts of order, or any concepts at all," Hampshire writes from his armchair. Things are looking rather different in the lab. In a hugely important study reported n today's New York Times and this week's issue if Science, the Columbia psychologist Herb Terrace got two rhesus monkeys, named Rosencrantz and MacDuff, to arrange collections of objects numbering anywhere from one to nine in the correct order. This not only entails that monkeys have an abstract sense of order and cardinal number, but also suggests that they might have a rudimentary capacity for stringing symbols together in sentences-that is, using language.
I saw Rosencrantz and MacDuff last night on CBS News. They were sitting in front of computer screens pointing to the objects with their index fingers in one order after another. They were gesturing quickly and looked to be enjoyably engrossed in the free exercise of this hitherto unsuspected cognitive ability. They looked happy--quite unlike the rhesus monkeys pictured in Animal Liberation in U.S. Airforce labs being shocked, gassed, and irradiated. And they looked a lot more intelligent than some of the Homo sapiens I have worked with.
Once again, Colin, this dialogue has been a pleasure, and I am happy to hear that arguments like those of Singer's have moved you to adopt a vegetarian diet-especially a "nonrigid" one, which suggest a likeable tolerance for those who, for one reason or another, have not grasped this moral message. Singer himself, in Animal Liberation, shows every sympathy for people whose hearts are in the right place but who find vegetarianism difficult in practice. For my part, I acknowledge the cogency of your argument against casual infanticide, and I will try henceforth to refrain from the practice.