Do you understand lasagne? Of course you do. But I understand it better because I know how to make it from ingredients none of which is lasagne. (If I were to 'make' lasagne by fusing eight squares of lasagne, and you were a philosopher, you would protest that I hadn't made lasagne but had 'presupposed' it. And you'd be right. That would be like making coffee by pouring eight cups of coffee into a carafe.)
It is tempting to suppose that what we know how to make, we understand. (He said with a sidelong glance in the direction of Giambattista Vico.) Let's give into the temptation. Suppose one day humans create a robot that is really conscious, conscious in the way I believe my wife is conscious. Whether or not I know that she is, in that tough sense of 'know' that entails being certain, I do not doubt for a second that my wife is a genuine bearer of intentional and non-intentional mental states. She has feelings just as I do and she thinks about things just as I do, and this is not a matter of ascription on my part as when I ascribe to my chess computer the 'desire' to inflict mate. Her verbal and non-verbal behavior do not merely simulate, even if exactly, behavior that is expressive of real consciousness; it is behavior that is expressive of real consciousness.
So suppose we have a really conscious robot fabricated to look like a woman, so well fabricated, let us assume, as to fool a gynecologist. If we know that that conscious being is a robot, we may find it hard to believe that she is really conscious. But suppose we can convince ourselves that our robot is really conscious and enjoys an 'inner' life just as we do.
What implications would this have for the mind-body problem? Would the existence of a really conscious robot that we had constructed from non-conscious material parts show that consciousness was a natural phenomenon that arises or emerges from sufficently complicated configurations of wholly material parts? Would it put paid to substance dualism? Would it show that there was nothing supernatural about consciousness? Could one refute substance dualism and the notion that consciousness (including self-consciousness and all spiritual functions) has a higher (non-natural) origin by building a conscious robot?
Many would say 'yes.' But I say 'no.'
If we make a really conscious robot, if we 'synthesize' consciousness and the unity of consciousness from non-conscious materials, what we have done is to assemble components that form a unified physical thing at which consciousness is manifested. But this neutral description of what we have done leaves open two possibilities:
1. The one is that consciousness simply comes into existence without cause at that complex configuration of physical components but is in no way caused by or emergent from that complex configuration. In this case we have not synthesized consciousness from nonconscious materials; we have simply brought together certain material components at which consciousness appears.
2. The other possibility is that consciousness comes into manifestation at the complex configuration of physical componets ab extra, from outside the natural sphere. A crude theological way of thinking of this would be that a purely spiritual being, God, 'implants' consciousness in sufficiently complex physical systems.
On both (1) and (2), consciousness arises at a certain level of materal complexity, but not from matter. On (1) it just arises as a matter of brute fact. On (2), consciousness comes from consciousness. On neither does consciousness have a natural origin. On (1) consciousness does not originate from anything. On (2) it has a non-natural origin.
Given these two possibilities, one cannot validly infer that consciousness is a wholly natural phenomenon from the existence of conscious robots. The existence of conscious robots is logically consistent with (1), with (2), and with the naturalist hypothesis that consciousness is purely natural.
My point could be put as follows. Even if we succeed in creating machines with (literal) minds, this has no bearing on the mind-body problem. This is because it leaves open the three possibilities mentioned. Suppose you are a conscious robot who is thinking about the mind-body problem. Substance dualism would be an option for you. You could not validly infer that your mind is not an immaterial substance from the fact that you were created in Palo Alto by robotics engineers. Same goes with me. I am not a robot, but a conscious animal who came into the world inter faeces et urinam. (Actually, if the truth be told, I came into the this vale of tears by Caesarean section; but let's not quibble: you came into it inter faeces et urinam.) But I cannot validly infer from the fact of my animal origin that my consciousness is a wholly natural function.
Now suppose naturalism is true. There is still the problem of the unintelligibility of the arisal of consciousness from brain matter, an unintelligibility that Colin McGinn, naturalist and atheist, has rightly insisted on. This unintelligibility will not be diminished one iota by the arrival of conscious robots should such robots make the scene in the coming years.