We will eventually see the rise of artificial intelligence, and even artificial consciousness.

The possibility of artificial intelligence is intriguing at least in part due to the fact that we have so poor a grasp on the question of intelligence and "thinking" in general. What does it mean, really, to be "intelligent?" What is really going on when someone is "thinking?" While all of us might have some opinions on these questions, it's very difficult to see how anyone could actually claim to know the answers beyond any reasonable doubt. If we truly did understand "thinking," for example, one would think that the question of building a machine to perform that function would be trivial – either that, or we would know, clearly and unambiguously, that the construction of an artifact which could think is, in fact, impossible – and we would know exactly why. But we don't really know what intelligence or thinking truly are. Lacking this knowledge, we're forced to fall back to some simpler statements of what we do know, and then to try to derive some better questions from there. We all (presumably) know that thinking exists, since we have direct experience of it. It also seems reasonable to assume that other people – those other creatures we see who look, act, and in general seem to be sort of like us – are also "thinking." But we have to admit that we do not, and perhaps cannot, truly know that this is so, at least not without some careful consideration. How is it that we can really say we know that someone else thinks, or is "intelligent?" As noted, we really base our assumptions here on the fact that other human beings seem to be "like us," and we already know that we think. But what if you encountered a form of life that wasn't at all like us in appearance, but seemed to behave or communicate like we do? What if, on the other hand, you found a living being who looked human, but who didn't at all behave or communicate like a human? To what degree might we say that other creatures on the Earth "think" – even though they don't look or act anything like us? Or what of the unfortunate person who, through injury to the brain, no longer behaves or communicates in a "human" manner at all, but who in purely external appearances obviously is still "human?" Appearance alone does not seem to be much of a basis on which to judge intelligence. Intelligent non-humans have also long been a staple of science fiction; we don't think twice about an SF story which features sentient aliens, and seem very willing to accept them even though they differ from us (in some cases, to an extreme degree) in appearance. But most people would claim that this is because, strange though these imaginary beings might be, they are still described to us as living beings – they are biological in nature. It seems fair to point out, though, that our bias toward granting living beings the ability to think is simply due to the fact that we have yet to experience non-biological thinking entities. But this really is no evidence that such things are impossible. At last, then, we come to the supposed main question: is it possible that a non-biological entity, and in particular a created entity – a machine – can legitimately be said to think? How can you really tell if someone (or something) other than yourself is "thinking?" In 1950, Alan Turing, one of the pioneers in computer science, proposed a rather simple test to answer this question. He described an experiment: Suppose you are in a room which contains a communications device of some sort – perhaps a PC running "chat" software. You can use this to converse with a "person" (exactly where they are is unknown, and really doesn't matter), and you can say or ask anything you want. But the "person at the other end" can be either an actual human being or a machine, and in this test they are in fact "switched in" at random. Turing claimed that if you could not reliably tell when you were talking to the human and when you were talking to the machine, then you had no choice but to recognize the machine as "thinking" at least as well as the human. Machines which are capable of passing the Turing test are still yet to be developed. However, given the pace of advancement in the computer industry over the past 50 years, few today doubt that this will eventually be achieved, and possibly fairly soon. The average person is becoming more and more comfortable accepting the notion of a machine which can "think" in this context. But, many of us say to ourselves, it's not "really" thinking, it's just a simulation of what humans (or if we're feeling more generous, "living things") do. When pressed to elaborate, most of us will resort to making a distinction between "thinking" as Turing means it, and actually possessing "consciousness." But this winds up at an argument precisely analogous to what we just covered with respect to "thinking." Each of us knows "consciousness" exists because we each experience it. We assume others like us also possess "consciousness," to a great extent because they seem to be "like us" and because they claim to be conscious, too. Again, though, we have to admit that we will never truly know if another being is conscious. It is always possible that the other beings we are dealing with are simply simulating consciousness well enough to enable us to believe that they are. We have nothing comparable to the Turing test for consciousness, and so wind up believing that other beings are conscious basically because they tell us that they are. What, though, if a machine – an artificial intelligence – were also to make that claim? On what basis could we accept or reject it? Failing a clear test for "consciousness," would we be forced to also "take the machine's word for it" in order to be consistent with how we treat similar claims by living beings? There's a sort of "back door" approach that is sometimes argued here – in the case of human beings, the "test" that is often applied for at least the capacity for consciousness is the detection of brain activity, as may be shown via an "EEG." A permanent loss of such brain function is called "brain death" and is commonly used as a determining factor in saying that the "person" in question is dead – whether or not the brain is physically intact (in a gross sense) and the other biological functions of the body continue on. "Consciousness," this supposedly tells us, relies on something more than merely being alive. But this argument works at least as well the other way: if "brain waves" are the test for the capacity for consciousness, then are we not saying that consciousness is inseparably linked to a purely physical phenomenon? And if consciousness arises from purely physical functions, it seems reasonable that it could arise in other "purely physical" entities of a nature other than biological – a mechanical and/or electrical being, for instance. Last-ditch attempts to keep "thinking" and "consciousness" as solely belonging to humans (or at least, living things) will then generally be forced to turn to claims of a "spirit" or "soul" as the quality which must forever distinguish natural living entities from artificial ones. But an honest inquiry here, it seems, must come to the conclusion that demonstrating the existence of a "soul" in humans and other "biologicals," and/or denying its existence in artificial beings, is at least as difficult as clearly answering the questions of "intelligence" and "consciousness." Unless is it argued that "soul" merely means the same thing as "consciousness," we cannot even claim to have direct experience of our own "souls" as a distinct property. The distinctive feature claimed for "souls" is that "soul" refers to a quality of "self" which survives physical death – i.e., it is something separate from, and not dependent upon, mere biological living. But if this is so, then it again seems that we have no basis for denying the possibility of a "soul" in an artificial entity; in fact, it would seem very arrogant to do so!