What is a person? The English term, "person," is ambiguous. We often use it as a synonym for "human being." But surely that is not what we intend here. It is possible that there are aliens living on other planets that have the same cognitive abilities that we do (e.g. E.T: The Extraterrestrial or the famous "bar scene" from Star Wars). Imagine aliens that speak a language, make moral judgments, create literature and works of art, etc. Surely aliens with these properties would be "persons"--which is to say that it would be morally wrong to buy or sell them as property the way we do with dogs and cats or to otherwise use them for our own interests without taking into account the fact that they are moral agents with interests that deserve the same respect and protection that ours do.
Thus, one of our primary interests is to distinguish persons from pets and from property. A person is the kind of entity that has the moral right to make its own life-choices, to live its life without (unprovoked) interference from others. Property is the kind of thing that can be bought and sold, something I can "use" for my own interests. Of course, when it comes to animals there are serious moral constraints on how we may treat them. But we do not, in fact, give animals the same kind of autonomy that we accord persons. We buy and sell dogs and cats. And if we live in the city, we keep our pets "locked up" in the house, something that we would have no right to do to a person.
How, then, should we define "person" as a moral category? [Note: In the long run, we may decide that there is a non-normative concept of "person" that is equally important, and even conceptually prior to any moral concept. At the outset, however, the moral concept will be our focus.] Initially, we shall define a person as follows:
PERSON = "any entity that has the moral right of self-determination."
Many of us would be prepared to say, I think, that any entity judged to be a person would be the kind of thing that would deserve protection under the constitution of a just society. It might reasonably be argued that any such being would have the right to "life, liberty and the pursuit of happiness."
This raises the philosophical question: What properties must an entity possess to be a "person"? At the Mind Project, we are convinced that one of the best ways to learn about minds and persons is to attempt to build an artificial person, to build a machine that has a mind and that deserves the moral status of personhood. This is not to say that we believe that it will be possible anytime soon for undergraduates (or even experts in the field) to build a person. In fact, there is great disagreement among Mind Project researchers about whether it is possible, even in principle, to build a person -- or even a mind -- out of machine parts and computer programs. But that doesn't matter. Everyone at the Mind Project is convinced that it is a valuable educational enterprise to do our best to simulate minds and persons. In the very attempt, we learn more about the nature of the mind and about ourselves. At the very least, it forces us to probe our own concept of personhood. What are the properties necessary for being a person?
Many properties have been suggested as being necessary for being a person: Intelligence, the capacity to speak a language, creativity, the ability to make moral judgments, consciousness, free will, a soul, self-awareness . . and the list could go on almost indefinitely. Which properties do you think are individually necessary and jointly sufficient for being a person?