This is actually a good question I think. As artificial intelligence and neurological studies continue to develop, the whole idea of a ‘Ghost in the Machine’ is going to be a crucial philosophical and scientific argument in this century to come. Catholics/Christians will need to clearly lay out our beliefs as opposed to materialism.
EntertheBowser:
Let’s say that we’re not really sure if Susan has a soul. How would we go about figuring out if she does or not? Or, equivalently, how would we tell the difference between SusanA, who has a soul, and SusanB, who is physically identical to SusanA, but has no soul?
First of all, every living thing has a
soul. Plants and animals have souls which animate them, their ‘life-principle.’ Animals have a more developed soul which is seen by the greater capabilites of their bodies (for example, memory and emotions).
In Catholic doctrine the soul is the *form *of the body, the objective universal of the creature which the body expresses. A higher evolved animal is such because it has a more complex soul. A creature is not complete without both its soul and its body. In the case of plants and animals, if the body is destroyed, the soul dissipates and the creature ceases to exist as a living being.
So, living thing=soul. If SusanB can be empirically verified to be
alive, and she has a *human ***body, **then she must thereby also have a human soul.
The special spiritual characteristics of the human soul are:
- free-will
- self- and god-consciousness (exemplified by arts/sciences and religion, respectively)
- special creation (directy received from God at conception)
- aeveternity (once it exists, it is indissoluble and survives the death of the body).
Free will and self/god-consciousness can be hindered from proper expression if the body is either born with, or acquires physical limitations (brain damage, limb-loss, blindness/deafness etc.). This is a consequence of the intimate unity between body and soul. The body must fully reflect the soul for the soul to fully express itself. Otherwise the person is ‘handicapped,’ incapable of wholly realising their humanity. This actually occurs to a greater or lesser degree in
everyone, (none of us are perfectly human yet***–except Jesus Christ and the Virgin Mary) because of the rift which Original Sin caused in Adam by removing perfect spiritual and physical harmony, but is rectified by the Resurrection.
Basically, if we can determine SusanB to be a
living *homo sapien sapien, *she has a spiritual soul. It is dogma, i.e. God has revealed to us that he imparts a spiritual soul to every physical human being, and there is no reason to believe (AFAIK) that this would not be the case with human clones, since a spirit (which only humans have) is not physically transmitted.
I would venture to hypothesise that no matter how complex and developed artificial intelligence becomes, human beings will never be able to create a free-willed, self-aware robot. There will never be a true ‘Ghost in the Machine.’ At the most, we may be able to create extremely complicated programs which can *simulate *free-will and self-awareness by responding to predetermined stimuli–but a program is still a program. If you program a robot to never kill a human being–it can never ‘decide’ on its own do so (only an accidental malfunction or external code–virus–could change the predetermined program).
It will be interesting in the coming decades to see materialists try to prove their ‘Ghost in the Machine’ hypothesis. I’m confident that us ‘moderate dualists’ will win points in this arena. Just like we did a century ago with the failed positivistic ‘Frankenstein’ experiment.
The dogma of the human soul is particularly critical because aspects of it are empirically falsifiable. If scientists can one day assemble a truly autonomous, self-aware, free-willed artificial intelligence, the Church will be forced to admit that the rational principle of man can no longer demonstrate his spiritual soul! If any one dogma is rejected, *all *of it is rejected. You can imagine what that would do to Catholicism. But of course, no dogma has ever yet been scientifically disproved
*****because of the remaining effects of Original Sin, even the baptised are incapable of fully expressing their humanity, as their bodies still do not perfectly reflect the spirit. This causes the well known struggle of ‘flesh’ against ‘spirit.’
I think that we come with the assumption that all human beings have souls, so we don’t need to test for them. Of course there’s always the weigh 'em right before death/right after death model, so you can measure how much the soul weighs. 
