Thursday, December 27, 2007

The computer objection

A. The Argument from Computers
Sometimes it is thought to be easy to refute any argument from reason just by appealing to the existence of computers. Computers, according to the objection, reason, they also are undeniably physical system, but they are also rational. So whatever incompatibility there might be between mechanism and reason must be illusory. However, in the case of computers, the compatibility is the result of mental states in the background that deliberately create this compatibility. Thus, the chess computer Deep Blue was able to defeat the world champion Garry Kasparov in their 1997 chess match. However, Deep Blue’s ability to defeat Kasparov was not the exclusive result of physical causation, unless the people on the programming team (such as Grandmaster Joel Benjamin) are entirely physical results of physical causation. To assume that, however, is to beg the question against the advocate of the Argument from Reason. As Hasker points out:
Computers function as they do because they have been constructed by human beings endowed with rational insight. A computer, in other words, is merely an extension of the rationality of its designers and users, it is no more an independent source of rational insight than a television set is an independent source of news and entertainment.
The argument from reason says that reason cannot emerge from a closed, mechanistic system. The computer is, narrowly speaking, a mechanistic system, and it does “follow” rational rules. But not only was the computer made by humans, the framework of meaning that makes the computer’s actions intelligible is supplied by humans. As a set of physical events, the actions of a computer are just as subject as anything else to the indeterminacy of the physical. If a computer plays the move Rf6, and we see it on the screen, it is our perception and understanding that gives that move a definite meaning. In fact, the move has no meaning to the computer itself, it only means something to persons playing and watching the game. Suppose we lived in a world without chess, and two computers were to magically materialize in the middle of the Gobi desert and go through all the physical states that the computers went through the last time Fritz played Shredder. If that were true they would not be playing a chess game at all, since there would be no humans around to impose the context that made those physical processes a chess game and not something else. Hence I think that we can safely regard the computer objection as a red herring.

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Sunday, September 09, 2007

Lewis and computers

C. S. Lewis lived before computers became the major force that they are now. I think he would not be impressed by the argument that
1) We know that computers are purely material systems.
2) We know that computers reason.
3) Therefore we know that material systems are capable of reasoning.

The reason he would not be impressed is that while computers do the "ratio" part of rational inference very well, the "intellectus" aspect is not to be found in the computer system itself, but is rather a "put in" by human programmers and builders.

He wrote:

"We are enjoying intellectus when we ‘just see’ a self-evident [basic] truth; we are exercising ratio when we proceed step by step to prove a truth which is not self-evident. A cognitive life in which all truth can be simply ‘seen’ would be the life of an intelligentia, an angel. A life of unmitigated ratio where nothing was simply ‘seen’ and all had to be proved, would presumably be impossible; for nothing can be proved if nothing is self-evident. Man’s mental life is spent labouriously connecting those frequent, but momentary, flashes of intelligentia which constitute intelluctus."

Can a computer "just see" that a truth is self-evident, like we do? Or does it accept those "truths" because we humans perceive those truths and get it to act as if it did as well? Isn't the latter obviously true? How can intellectus be possible for computers, even jazzy neural nets?

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