The Computational Universe

In his article, “Is the Brain’s Mind a Computer Program?” Searle provides a very compelling argument to show that a computer program can never duplicate a human mind.  He readily allows that it is theoretically possible for a program to simulate the behavior and fool humans into believing that the responses, whether verbal from the chatbots or physically reactive from a robot like Kismet, are human, which would mean that the machines could pass the Turing test.  However, as Searle makes quite clear, the ability to pass the Turing test is not the same as thinking.

Yet, I believe that it would be a misinterpretation to declare that Searle is arguing that AI is impossible.  Rather, I believe that Searle is arguing that an attempt to reach AI solely through computer programming is foolhardy and doomed to failure.  Instead, we may interpret Searle to suggest that trying to separate the programming from the physical construct in which it is implemented is comparable, and equally incorrect, as attempting to draw a concrete distinction between the mind and the brain.  As he states, “It is best to see strong AI as one of the last gasps of this antiscientific tradition, for it denies that there is anything essentially physical and biological about the human mind.  The mind according to strong AI is independent of the brain.  It is a computer program and as such has no essential connection to any specific hardware.” (Searle, 31)  And this is precisely why Searle believes that the strong AI approach is plainly wrong.  He believes that it is wrong to separate the mind from the very real, physical substance that is the brain.  A computer program cannot replicate the mind because the mind is inextricably connected to the brain.  Thus, I believe that Searle does not deny the possibility that AI can be reached, but does so only on the condition that we acknowledge that AI requires an interaction comparable to the interaction between the brain and what we may more scientifically call consciousness.  A computer version of the human brain is needed.  Searle goes on to put a special emphasis on the uniqueness of the human brain and neuron.  This emphasis is hard to justify, but does not seem ridiculous to assume.

But, it is precisely this emphasis on the special properties of the organic human brain that Brooks contests.  He believes that it might be possible for silicon and steel to make a system that can function in a way similar to that of the brain.  And he presents an argument for it.  Whether or not we subscribe to this argument ultimately depends on our deeply ingrained beliefs about human existence.  Brooks makes no attempt to change these beliefs.

Thus, it is important that when we approach this issue we take Brooks’ point to heart.  We must not let our personal emotions and beliefs about whether or not we are simple machines completely cloud our judgment.  It is impossible for our beliefs not to sway us, but we should be conscious of this and endeavor to fully consider the opposite side.

With that said, I am currently inclined to side with Brooks.  I have no strong reason to believe that human beings are not machines, so I will not deny the possibility that silicon and steel could one-day duplicate human behavior and consciousness.  However, that day has not yet come, so I also see the point of Searle’s conclusion… at least for the moment.

I do not know about the rest of you, but I have always taken the Internet for granted so Tim Berners-Lee lecture was a real eye-opener.  I always knew that there was a time before the wild world wide web, but I never really sat down and thought about how much we owe to its early founders.  And even more interesting (although a little hard to follow) was the thought of how the web will evolve and how it will impact our lives.

I grew up in a wired household.  I have only dim memories of the days when I would actually pick up a pen and sign a birthday card before it was shipped off to an aunt or uncle via snail mail.  And now even the days of birthday cards, sweetly tucked in their handwritten envelopes, are winding down, doomed by the abundance of free and instantaneous e-cards that you can send guilt-free on the day of the person’s birthday.  I do admit that I feel a slight pang of regret to see such time-honored traditions phased out, but I nonetheless can’t help shrugging my shoulders and marching on to the drums of progress. 

But who knows, maybe a day will come when we are so completely wired that what we consider normal human contact and interaction will be so changed that humankind as a whole decides to abandon the cyber-highways for good.  Now THAT is an interesting, albeit outlandish and improbable, prophecy for the future of the web.

Before I entered this course computation seemed very intimidating in its complexity.  Now that we are a couple of weeks into this course I realize that this type of computation, although certainly still intimidating, can be deciphered.  The Turing machines were perhaps my biggest breakthrough in this regard.  I do not have much background with programming or computers, so the code used to write software and the working of the hardware always eluded me.  The Turing machines showed how complex computation could be achieved within a very simple system.  This system uses only a handful of commands and an infinitely long one-celled tape composed purely of 0s and 1s, but using these tools can do seemingly impossible things.  It is a universal program that can simulate any program.  It can perform incredibly challenging calculations.  It can reproduce itself forever.  Such range and got me thinking what exactly it couldn’t do.  The Halting Problem was perhaps the most disappointing case.  Some questions simply elude the Turing machine.  It can never conclusively determine whether a Turing machine will halt.

But the Turing machine also has other limitations and lessons in my eyes that are not directly tied to its limitations. First, the Turing-Post programs tend to make me try to oversimplify computation.  This is obviously foolish.  Second, we must remind ourselves that although computation can seemingly be simplified to a very simple code we as human beings are still doing things that are far beyond the capabilities of our most sophisticated machines.

Most of us are familiar with the story of the Tower of Babel.  This Christian fable tells us that humans once shared a single language.  They supposedly gathered together on a plain “in the land of Shinar” and thrived.  The common language allowed them to cooperate and coexist with each other.  As their civilization and technologies grew they decided to build a tower of gigantic proportions, a monument that would cement their union as a people.  The Lord looked down upon their work and decided to intervene.  He took the communal language away from his creations lest they do things that challenged his power, so he scattered them across the Earth.  With the communal language no longer accessible the people remained scattered and could not finish the work on the tower and their beautiful city.  According to this story the many languages of the world sprung from God’s whim.

Well, it seems that we did not learn from the several millennium where we struggled to comprehend each other’s babbling attempts to communicate.  With the birth of computers we were given a chance to create a new language that we could collectively develop and enhance to direct our computerized creations.  Alas, we did not do so.  Instead, thousands of computer languages (Bill Kinnersley has listed more than 2,500) were created, some of them with resolvable similarities but others with differences as pronounced as those between English and the !Kung dialect (the orthographically unusual word !Kung refers to a language spoken by a group of San in southern Africa; the more you know).  Here is a brief history of the incredible fragmentation of computer languages.  We decided to tear down our own Tower of Babel, creating languages that often made a certain task simpler, but thoroughly obfuscated the communal understanding of programmers across the globe and across the hall.

Thankfully, we do not have to negotiate between 2,500 languages in this course.  Instead, an alternative language is used that bridges the gap between the other computing languages and simplifies the programming for those without much programming experience.  It is called “pseudocode,” which literally means fake code but can be more appropriately described as simplified and streamlined version of code.  Because of this pseudocode makes me happy.  Very happy.  It has the same fundamental features of computing programs (e.g. ability to perform arithmetic, variables, conditional and loop statements, etc), but it uses a syntax that is based on English commands.  Thus, it allows us to learn about computer languages in general without having to study individual languages.  Thanks to this we can build our own little Tower of Babel, not out of bricks and mortar, but out of the equivalent of children’s building blocks.

Hey All,
My name is Jesse Wright and I am from the Republic of Panama.  Most of you are probably familiar with the canal and the cool hats that share its namesake (incidentally, Panama Hats are not actually made in Panama; they are from Ecuador).  In case you did not know, Panama is also a very nice and warm place to be between January 1 and December 31 of every year, as opposed to New Jersey which is tolerable on June 21 between 3:02 and 3:08 PM on leap years when the moon is full and Mr. T is not pitying a fool (which is not very often).  Case in point, little white bits of the sky are all over the ground outside.  It is 86 degrees Fahrenheit right now in Panama (Weather.com taunts me so).  So, the answer to the question, “But why is the sun gone?” is that the sun just likes Panama a whole lot more.

But all joking aside, I am enjoying myself here at Princeton.  I am currently on the Economics track and am looking forward to many more years of supply and demand graphs.  I took this course because although I am fairly proficient with computers I always wanted to know more about the deeper principles and processes.  Computers are so prevalent in my life that I figured that I should get to know them a little better.  Also, I want to find out whether it is just a random coincidence that my toaster keeps shooting blackened toast at me every morning or if it is harboring a grudge because I once tried to toast a bagel after I had put cream cheese on it.

Update 5:29 PM on 02/13/06: By the way, I use a Windows PC.