Continued from my second rebuttal «
Steve has now posted his second rebuttal. I am reproducing it here for ease of reference.
An interesting response, but it suggests something to me. A plan for a castle in the sky. It looks glorious (to some), with all the intricate theological architecture. I do wonder, though, how the castle is intended to stay up there. Science and reason can build castles too. But we find it is better to build from the ground up. You get better foundations.
Science and reason build on more solid foundations because of they are based on humility; the Copernican Principle: we aren’t the centre of everything. This principle applies in many ways. The Earth is not the centre of the cosmos. The Sun isn’t the centre of the galaxy. The galaxy isn’t the centre of the Universe. It looks increasingly likely that the universe isn’t special either. The laws of the universe are the same everywhere, and everywhen. The Copernican principle can also be applied to time: this isn’t a special time in the universe. It can also be applied to biology. We aren’t that special as a species, and it is likely that more complex and capable species will come after us.
The humility we get from such an approach has yielded dividends: we have discovered aspects of reality that are way beyond anything we have imagined (and we still find hard to comprehend them), such as the physical nature of the cosmos. We are also researching the human brain and mind, and much of my discussion has been influenced by the results of that research. This research proceeds because we don’t make assumptions about the nature of reality. We don’t assume in advance limitations on the capabilities of biological systems to think and reason. We don’t declare what is and isn’t possible for physical systems to achieve in this regard.
So, on to specifics arguments you make.
Here is a premise: All men are mortal. Here is another: Socrates is a man. Here is a conclusion: Socrates is mortal. Do the propositions cause the conclusion? No.
“But if my belief that Socrates is mortal is caused completely by the conjunction of prior physical states in my brain, then it is not caused in any part by virtue of its premises. But we know from (I) that it is self-refuting to claim that premises have no causal role in forming conclusions.”
It isn’t caused by premises. It is caused by the processing of the mental representations of premises.
Let’s express your statements in formal logic:
“FOR ALLx: Hx -> Mx”
“EXISTSx: Hx AND x=a ”
“THEREFORE: Ma”H = Human, M = Mortal, a = any entity.
All I need to establish is that the use of this logical structure is implied by the words you use, and that the brain can implement this structure. The words acquire meaning through a consensus about their use, so that part of the argument is easily dealt with. Now, can neural networks implement such logical structures? The answer is unquestionably yes, they can. We know this is possible in principle because we can implement such logical structures in computer systems, and because neural networks are capable in principle of any functionality of such computer systems. However, the structures certainly won’t be implemented in anything like the way that we build or program computers. They will be the result of the training of our neural networks by years of experience and learning. We learn the rules of the game (as I will discuss later).
That is all I need to show that the logic you describe can be dealt with by the physical substance of a brain. We know that certain words imply the use of certain logical structures, and we know that the logical structures can exist in the substance and activity of the brain.
At this point, I feel that it is worth considering in detail what we mean by “meaning”. Meaning comes from recognition, and recognition is a function of memory, which is certainly physical. Meaning also comes from consensus. We have developed methods of interpretation and procedures of logical deduction. When we communicate with others, we don’t make random noises and expect gibberish back. We use words that we have come to expect will produce a known response. This is what “meaning” means- this connection between input and output. So why do we have personal recognition of meaning, as against something that is related to communication with others? It is because our minds model themselves as well as the minds of others. Communication, at least in terms of language (which is what we are largely talking about when we consider reasoning) is a conscious activity. We need to make conscious choices about how to influence others with language. This means we have to either rely on experience, or test how we intent to communicate against mental models. This testing need not be conscious – only the results of it need to be experienced. We experience results of such testing as meaning. This all comes from a solid foundations: our need to deal successfully with others of our kind. There is no magic ingredient, nothing unphysical. No need for any “mental realm”.
This building up of meaning can be thought of as like playing a game, but an amazingly complex one. In his novel “The Player of Games”, Ian M. Banks describes Azad, a game with an astoundingly rich set of rules, and that can be played in countless ways. People can choose to cooperate or compete, and the game-play itself can be influenced both by the decisions of the players and by chance. The game is so rich and complex because it represents society and strategies can embody different philosophical positions. Language is like that – although there is a foundation of some rules, new meanings arise all the time and the rules of the game can change. But, underneath it all, there are still rules, and as we know artificial intelligences are starting to beat humans in even the most sophisticated games, and they are starting to be able to play the language game too.
Well, the argument I am forwarding is precisely that physical processes cannot in principle constitute reasoning. Therefore, if a physical system gives the appearance of reasoning, either it is an appearance only, or something more is going on than we are able to see using only physical means. There is simply a disconnect, in impassable bridge of principle between what is needed for reasoning to be reasoning, and what is possible given a purely physical world. In other words, if reasoning were indeed a physical process only, then its very nature would not actually be what we understand reasoning to be.
This is because you are attempting to define reason as something that can’t be performed by physical systems. I have warned of this before:
“I also feel we need to stay focused on what human reasoning consists of, and not be tempted to abstract matters to ever higher levels so that they are always beyond whatever a materialistic view of the world can explain. One of the tools of reasoning is Ockham’s Razor. We should stick with the simplest level at which we may be able to begin to explain things, and only move up from there if absolutely necessary. We also have to be careful about how we would justify moving to a different level. The history of science and reason has taught us that common sense, incredulity and ontological arguments are not good justifications.”
The examples of reasoning you have given involve the application of logic. Logic is a deterministic procedure, and is the basis of all computers. I can remember how impressed I was when I first learned to program computers as a teenager in the 70s. I could barely believe that I could type some instructions that were pretty much English and some crystalline circuitry could interpret them. It was a revelation. I have been hooked on programming ever since. However, I learned how it was achieved: the systems of logic gates and information storage. There is no doubt that what a computer does is logic. To claim otherwise would be equivalent to saying that a pocket calculator doesn’t truly calculate, as all it is doing is moving electrons around. However, we do say that this small hand-held device does calculate because we see no need for there to be any mystery about the process. The calculator does its job because its structure contains information (in the form of circuits) that represents the logical systems used in arithmetic, by restricting the paths of electrical currents. Information is encoded in this lack of freedom, this order in the structure. There is, equally, no mystery about the processing of logical statements by electronic devices. From what we have discovered about the operation of neural networks, we have made considerable progress in explaining how the functions of the human mind can arise. The brain contains information that constrains the interaction of neurons – pathways that arise both from development and from learning.
Something else that is important to understand is that if we are to discuss human reasoning we have to view it from an objective position. We determine if another entity (be if silicon or biological) can reason by observing how it responds to our interactions with it. We ask the entity questions and we can see by the response if the entity has apprehended the meaning. If an entity responds in a way that seems to indicate that it has found meaning in our communication, that has to be enough. We can’t ask for the entity to reveal its physical nature because of some prejudice towards carbon-based life forms.
”But there could exist a mind which is infinite and unlimited unified”
We have not the slightest reason to believe this is the case. The only minds that we have been able to study are our own, and we know that they are finite. Even if one were to postulate some kind of dualism (which I don’t accept in this debate), we have already established it would have to work hard to keep up with the changes in the physical brain (as when the brain experiences changes due to drugs, or suffers trauma). There has been no suggestion here of the mechanism by which the dualist brain manages this remarkable ability.
A mind is itself already unified; it contains no parts which must in turn be unified; and neither could it, or it could not act as the origin of a unifying principle in the first place, but rather would rely on some other unifying principle first. (Memories, thoughts, and the like, it should be recognized, are reflections of a pre-existing plurality outside the mind.)
The idea of a mind being “unified” is a pretty odd suggestion. A mind would not work if this were the case. If memories and thoughts are reflections of yet another realm outside the mind, then it seems we have moved beyond dualism into yet more fragmentation of reality. This is all part of the scaffolding of the proposed castle-in-the-clouds. Not only do we have to assume the nature of the “dual” mind, with its neurone-state-sensors, but now we have to assume some other “plurality”, which somehow “reflects” “onto” a “mind”. As I described earlier, unless solid rational evidence for this dualism, with its apparently endless series of metaphysical extras, can be provided, this is all question-begging, and cannot be accepted.
Finally, I would like to deal with your suggestion that, somehow, involved in all this, is the Trinitarian Christian God. I think here you reveal the inconsistency of your position you are attempting to describe reason using the unreasonable, and logic to defend the illogical. The Trinity is a logical contradiction. This is a mereological (part/whole) ontological error. Let’s look at this formally:
1. D is defined as {A, B, C} (God defined as {Father,Son,Holy Spirit})
2. A=D AND B=D AND C=D (God wholly present as Father and wholly present as Son, and wholly present as Holy Spirit)
3. A=B=C=D (from 2, because ‘=’ is a transitive relation)
4. D := {A, A, A} (from 1 and 3)
5. D := {B, B, B} (from 1 and 3)
6. D := {C, C, C} (from 1 and 3}
7. D := [D, D, D] (from 1 and 3)
8. D := {{A, B, C}, {A, B, C}, {A, B, C}} (from 7 and 1)
Conclusion 1: statements 4-8 contradict statements 1 and 2.
So, 1 and 2 lead to contradictions – which means that tri-unity is logically impossible. In statement 8, the elements of the sets included in D are defined again as {A, B, C}, in which the ‘A’s, ‘B’s, ‘C’s are again said to be equal to D and thus defined as {A, B, C} – it’s an infinite regress.The existence of the Trinity is contradictory. It is equivalent to a statement that a circle is a square. Of course, we can believe contradictions, but it is not appropriate to allow them in a discussion about reason, that is itself supposed to be using reason to make a case.