The Free Willies: Are computers like humans? Are humans like computers?
The World Wide Web, itâ€™s like a giant human mind the way it processes billions of pieces of information. Someday it will become so smart it takes over the world. It will be able to think instead of us. Or so some cognitive scientists say.
Your new computer too, it thinks so fast. The better computers get, the more obvious it is that minds are like them. Pretty soon there will be nothing humans can do that computers canâ€™t. Or so some cognitive scientists say.
Others challenge these views. Sure, computers and the Web look smart, but so do telephones and the telephone service. After all, the phone rings, and you pick it up. The tiny speaker generates for you a disembodied voice speaking words of wisdom, very similar to the wisdom you get from your mother, your friends, or the folks who just know you want to buy or donate to something, right?
But no one is naÃ¯ve enough to think the phone or the phone system is the source of that intelligence. Itâ€™s just a conduit for real human intelligence, which is different from the kind of stuff that computers, the Web, or phones and phone systems produce.
The information we get from our machines wouldnâ€™t mean anything without us to perceive it. A computer is phenomenally good at running algorithms, precise recipes for transforming one statement into another. But changing the forms of things is really just physics and chemistry until a real human steps in to interpret the output as meaningful.
Sure, to you, the final tally your bookkeeping software generates means lots for your prospects of getting a tax refund this year, but without a human like you to find them meaningful, the computer-generated squiggles on the screen are meaningless.
Still, the fact that computer processing substitutes perfectly for a lot of human thought must mean that a lot of what computers do is exactly like what humans do.
And who knowsâ€“though we would be loath to admit it if it were true, maybe when we read the squiggles the bookkeeping software generates, weâ€™re no different from a computer peripheral that translates one kind of information into another. If the squiggles mean you get a tax refund, you buy a new car. If not, you donâ€™t. Itâ€™s just an if/then statement like youâ€™d find in any algorithm. Maybe everything people do will eventually be translatable into computer logic.
But think of the full implications of that. If all thought turned out to be algorithmicâ€“just the precise one-to-one translation of one statement into another that follows exclusively from itâ€“then weâ€™d live in a predetermined world. Every future thought could be deduced from every present thought with no human guesswork involved. Like the version of causality I talked about last week, in which all states follow precisely as the necessary outcome of all prior states, and the universe is a clockwork where every future event is predictably foretold by every prior event. What a nightmare of determinism, eh?
That kind of determinism may sound creepy, but to many people over many generations itâ€™s been their greatest yearning. Deducing truths about what we should and shouldnâ€™t do may take the fun out of lifeâ€™s adventure of discovery, but for many of us lifeâ€™s exploratory adventure is so scary itâ€™s no fun at all.
You may recognize the feeling, a time when you felt unqualified to govern your own life. I remember one particular low point. It felt like spirituality-at-gunpoint. My past looked so disappointing and my future so doomed that I could only afford to â€œbe here now.â€ I felt so incompetent that I was ready to submit to some higher authority:
â€œUm, Iâ€™m blowing it here. Iâ€™m no good at free will. Would somebody please take over for me?â€
I got over itâ€“but man, do I know what itâ€™s like to want someone to give you a cheat sheet, to tell you what exactly to do to make sure that everything comes out as good as possible. The â€œfree williesâ€â€“fear of the unknown and oneâ€™s own incompetence at handling free willâ€“lends a clockwork universe some appeal.
For some people the free willies are a function of temperament. Theyâ€™re perfectionists, or so chronically anxious and easily flapped that determinism would be a relief. But any of us, regardless of temperament, can run into high-stakes circumstances in which room for error is so terrifyingly small that weâ€™d just love to know perfectly what to do. People pray for answers.
Some of us crave absolute truths all the time and all of us crave absolute truths some of the time. The ability to deduce all of lifeâ€™s truths and falsehoods; shoulds and shouldnâ€™ts once and for all would be a dream and a nightmare come true.
The bad and good news is that itâ€™s not possible. To talk about why itâ€™s not possible, Iâ€™ll have to delve into exactly what it means to deduce truths. Deductionâ€“its power, its pitfalls, and its place in life in general and in your life in particular. That will be next weekâ€™s topic.
Deduction: The dream and nightmare of absolute certainty
Last week I began comparing and contrasting computers and minds, examining both human intuitions and appetites regarding the prospect that our minds are governed by the same kind of direct one-to-one-correspondence kind of cause-and-effect we see in the physical world (Aristotleâ€™s efficient cause). If minds are really like computers, just translating information from one form to another by determinate rules, then we would live in a deterministic universe. Just as Laplace thought, if you knew the determinate laws, you would be able to deduce all future states from past states. Weâ€™d be able to deduce all of tomorrowâ€™s truths from things known today. On the one hand weâ€™d miss out on the fun of surprises; on the other we would have gotten rid of uncertainty, the root of all anxiety.
A word then about deducing and its connection to absolutely predictable computer-like causality. Deduction is the master recipe for â€œreasoning from the general to the particular.â€ If you start by knowing a certain kind of thing always has a certain property, then obviously any particular example of that thing will have that property. A deduction takes the form:
If A then B.
If [human] then [mortal].
If you then apply this to a certain thing X, the statement becomes:
If [X is A] then [X is B].
If [Socrates is a man] then [Socrates is mortal].
Hereâ€™s the classic syllogism used by Aristotle to introduce the concept of deduction:
All men are mortal (which translates as If A then Bâ€“If man then mortal).
Socrates is a man (which translates as X is A).
Then Socrates is mortal (which translates as X is B).
Deduction is airtight logicâ€“a one-to-one correspondence whereby inputting certain premises yields unambiguous answersâ€“necessary conclusions with no room left for doubt. Deduction is the basis for all of what computers do. Itâ€™s what makes them so reliable through enormously complex algorithms. Deduction governs the production of all mathematical proofs, and it is the exclusive source of every powerful truth in math and geometry.
For over 2400 years, some people have been hoping to derive moral truths exclusively by deduction as well. Socrates himself appears to have believed it possible, and many religious leaders have thought so too. Start from the generalizations one can find in the bible, Koran, Tao, or any other great religious guidebook, and by deduction derive every other possible truth. Youâ€™ll have a complete recipe for living right.
Just think of all the hassle this would save. We would know the true laws and, so long as everyone followed them, things would be perfect or as close to perfect as possible. We wouldnâ€™t have to wonder if we were doing the right thing. Everybody would have to surrender to the law, because debating the right answer to a moral deduction would be as ridiculous as debating the right answer to a long division problem.
By now most serious scholars have given up on the deductive approach to finding moral truths, partly perhaps because the idea of a predetermined world spoils lifeâ€™s adventure of discovery, but primarily because fundamental problems interfere with attempts to deduce absolute moral truths. For one, since deduction always has to start with a generalization, you canâ€™t really do deduction from the ground up. The ground is laid by truths not derived by deduction. For example, this is an airtight deduction:
All men are platypuses.
Socrates is a man.
Therefore Socrates is a platypus.
Itâ€™s airtight but wrong. Garbage in; garbage out. The first premise is false. So yes, while it seems likely that all men are mortal and Socrates is a man, or in math, that 1+1=2, or a line is two-dimensional, when it comes to deducing moral truths, the premises will always be more iffy. A weak foundation makes for a weak structure and so thereâ€™s no escaping the guesswork.
There are two more parts to this story. For one, itâ€™s time to spell out what this guesswork entails, and that Iâ€™ll do next week. For the other, Iâ€™ll come back to computers and specify the parallels and contrasts to human thought-the practical payoff of which is some guidance about what processes we should and shouldnâ€™t realistically want or expect to put on automatic.