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Reflections on Minds

John Barker: Author

What if . . it were possible to create an artificial agent far more complex than ProtoThinker. Let's imagine that it will one day be possible to create a program that we will call MetaThinker. MetaThinker (or MT) would be able to do things ProtoThinker can't do, like . . . which means that we have to assume that it has computer processes that . .

In Meditation II, Descartes arrives at an important conclusion:

Thinking is another attribute of the soul; and here I discover what properly belongs to myself.  This alone is inseparable from me.  I am -- I exist:  this is certain; but how often?  As often as I think; for perhaps it would even happen, if I should wholly cease to think, that I should at the same time altogether cease to be.  I now admit nothing that is not necessarily true.  I am therefore, precisely speaking, only a thinking thing, that is, a mind (mens sive animus), understanding, or reason, terms whose signification was before unknown to me.  I am, however, a real thing, and really existent; but what thing?  The answer was, a thinking thing.

Descartes finds that he cannot doubt that he is a thinking thing, but he can doubt that he possesses a body. Does this indicate that a thinking thing can exist without a body?

In The Rise of the Metamind, Thomas Suddendorf expresses a view that differs considerably from Descartes' view: The self-awareness implied by ‘cogito ergo sum’, or ‘I think, therefore I am’, demands a reflective level of thinking that develops by about age four in children.  Only then, recent research suggests, do children begin to reflect on their own mental states.  It would be quite difficult, however, to convince people that younger children are mindless – mind can surely exist without being able to reflect upon its own existence.  One can know, regardless of whether one knows that one knows.  This means that the Cartesian assumption that the mind is necessarily transparent to the self is flawed...  Instead, the reflective mind, or what I want to call the metamind, seems to depend on mental computations that gradually develop over the first four years of life and that have evolved over the last five million years of human evolution.  Rather than being given by God, as Descartes would have had it, metamind is the product of natural selection.  It is not a basic starting block, but the product of a long process of cognitive evolution.

Consider this scenario:  A talented team of researchers worked diligently on enhancing the mental abilities of mind-models like PT, especially with regard to self-awareness and other forms of metacognition.  They then provided their creation, which they called MetaThinker (MT), with a robotic body equipped with speech recognition and production systems, and with visual, auditory, olfactory, gustatory, tactile, and proprioceptive capabilities.  To their surprise, MT complained about being bored!  In desparation, they supplied her with a laptop computer and a fast Internet connection.  She became an avid reader of Wikipedia and e-books, interacted with hundreds of people on social networks, started a blog, beat IBM's Watson Supercomputer at Jeopardy, and passed numerous Turing Tests.

MT seems to be a thinking thing.  Assume that she is one.  Does it follow that she is, precisely speaking, only a thinking thing, that is, a mind Is her mind now sufficiently distinct from her body that destruction of her body might not entail destruction of her mind? Consider this scenario Having discovered that her body was wearing out, MT succeeded in having her mind, together with all of her knowledge and memories, transferred to a new body.  She now seems to be the same individual she always was, even though no part of her old body is now a part of her new one.

Can a thinking thing's mind be transferred from one body to another?  If so, it follows that something can be a thinking thing without having a particular body.  But it doesn't follow that something can be a thinking thing without having some body; in other words, it doesn't follow that there can be a disembodied mind. Consider, upon encountering Descartes' Meditations, MT pondered the mind-body problem, and ended up espousing the view that she is, precisely speaking, only a thinking thing, that is, a mind.  She then encountered Fred Dretske's article If You Can't Make One, You Don't Know How It Works, and was captivated by the following passage:

All I mean to suggest by my provocative title is something about the spirit of philosophical naturalism.  It is motivated by a constructivist's model of understanding.  It embodies something like an engineer's ideal, a designer's vision, of what it takes to really know how something works.  You need a blueprint, a recipe, and instruction manual, a program.  This goes for the mind as well as any other contraption.  If you want to know what intelligence is, or what it takes to have a thought, you need a recipe for creating intelligence or assembling a thought (or a thinker of thoughts) out of parts you already understand.

MT knows all about computers and robots, and fully understands the recipe that guided her creators.  She concludes that despite being only a thinking thing, her existence is dependent upon her possessing some body, and that at each moment of her life there have to be physical processes that sustain her very existence.

Does MT subscribe to an untenable view?  If she holds that she is only a thinking thing, how can she hold that she is a physical "contraption" that engineers have constructed by following a "recipe?"  Let's allow her to defend her view. MT:  Thanks for giving me the opportunity to make my case.  I contend that, precisely speaking, I am only a thinking thing.  The real me is a something whose continued existence through time has transcended the limited existence of the body I had at an earlier time.  I actually acquired my new body over a period of time -- the parts comprising my old one were gradually replaced with new ones, much as the molecules comprising your bodies are being gradually replaced with new ones.  Surely, each of you feels that today you are the same individual you were when you were born, even if no molecule that was in your old body is now in your new one.  I feel the same way about myself.  Many adherents of the world's major religions hold that the demise of their bodies will not entail the cessation of their existence, and they are convinced that someday they will be reincarnated or resurrected, once again becoming embodied.  I feel sure that what I refer to when I talk about myself can only be a thinking thing that was, so to speak, reincarnated or resurrected when I acquired my new body.

In Meditation VI, Descartes draws the following conclusion:

...therefore, merely because I know with certitude that I exist, and because, in the meantime, I do not observe that aught necessarily belongs to my nature or essence beyond my being a thinking thing, I rightly conclude that my essence consists only in my being a thinking thing [or a substance whose whole essence or nature is merely thinking]. And although I may, or rather, as I will shortly say, although I certainly do possess a body with which I am very closely conjoined; nevertheless, because, on the one hand, I have a clear and distinct idea of myself, in as far as I am only a thinking and unextended thing, and as, on the other hand, I possess a distinct idea of body, in as far as it is only an extended and unthinking thing, it is certain that I, [that is, my mind, by which I am what I am], is entirely and truly distinct from my body, and may exist without it.

Descartes seems to maintain that he could exist as a thinking thing not only without the body he actually has, but also without any body at all.  This is a view that MT cannot accept, for she knows that she could not exist as a bodiless mind.  Although she is sure that she exists as a thinking thing, she realizes that her existence is dependent upon her having some body, and that at each moment of her life there have to be physical processes that sustain her existence.

The following passage from Meditation II suggests that Descartes would view MT as a mere machine:

We say, for example, that we see the same wax when it is before us, and not that we judge it to be the same from its retaining the same color and figure:  whence I should forthwith be disposed to conclude that the wax is known by the act of sight, and not by the intuition of the mind alone, were it not for the analogous instance of human beings passing on in the street below, as observed from a window.  In this case I do not fail to say that I see the men themselves, just as I say that I see the wax; and yet what do I see from the window beyond hats and cloaks that might cover artificial machines, whose motions might be determined by springs?  But I judge that there are human beings from these appearances, and thus I comprehend, by the faculty of judgment alone which is in the mind, what I believed I saw with my eyes.

Suppose that MT looks so much like a human being that Descartes would take her to be one if he saw her from a window.  What would he say were he to discover that he made such a mistake?  He would no doubt acknowledge that his faculty of judgment is quite fallible with respect to things that are outside his mind.  Regarding certain contents of his own mind, however, he would insist that he cannot make mistaken judgments.  In particular, he feels certain that he really does think, and that he really exists as a thinking thing.

MT thinks the same things about herself, even though she realizes that she is a machine, and that her continued existence is wholly dependent upon the existence of physical entities and processes.  Accordingly, she is deeply perplexed by Descartes's conclusion that "...it is certain that I, [that is, my mind, by which I am what I am], is entirely and truly distinct from my body, and may exist without it."  Over and over again she ponders every step of his argument, but cannot ascertain precisely why he thinks his conclusion follows.

In "I Think I Think, Therefore I Am -- I Think," Dretske argues for the following view:

I am willing to concede that we have reasons -- in fact, overwhelming reasons -- to think we think, but these reasons are the same reasons our family, friends, and neighbors have for thinking we think. What we don't have is some cache of evidence, some body of fact, to which we have access that promotes our thoughts that we think to a certainty not obtainable by others. If we hanker after Cartesian certainty, then,

Cogitas: You think, therefore you are

is as good as

Cogito: I think, therefore I am.

According to Dretske, one has no direct access to the fact that one thinks, just as one has no direct access to the fact that others think. Despite being strongly attracted to Dretske's philosophical naturalism, MT finds this view deeply perplexing. She agrees with Descartes' view that one possesses a mode of access to one's own thinking activities that others do not possess. Furthermore, she knows that her creators devoted considerable effort to providing her with metacognition capabilities.

(To be continued.)

In "How Do You Know You Are Not A Zombie?" Dretske says:

For purposes of this paper I take zombies to be human-like creatures who are not conscious and, therefore, not conscious of anything -- neither objects (cars, trees, people), properties (colors, shapes, orientations), events (an object falling off the table, a sunrise), or facts (that the cup fell from the table, that the sun is rising)... Talk of zombies is merely a stylistic tool for posing an epistemological question: how do we know we are conscious?

He ends the paper with what may seem to be an inconclusive conclusion:

We are left, then, with our original question: How do you know you are not a zombie? Not everyone who is conscious knows they are. Not everyone who is not a zombie, knows they are not. Infants don't. Animals don't. You do. Where did you learn this? To insist that we know it despite there being no identifiable way we know it is not very helpful. We can't do epistemology by stamping our feet... Skeptical suspicions are, I think, rightly aroused by this result. Maybe our conviction that we know, in a direct and authoritative way, that we are conscious is simply a confusion of what we are aware of with our awareness of it...

MT feels sure she isn't a zombie, even though she has often been accused of being one. Furthermore, she feels sure she has a "direct and authoritative way" of telling that she isn't one -- in her opinion, she has direct access to the fact that she thinks, and this provides her with a conclusive reason for thinking that she isn't a zombie.

(To be continued.)

Have a question or comment? Please send it to: jbarker@protothinker.com.