David J. Kinniment He Who Hesitates is Lost: Decisions and free will in men and machines. He Who Hesitates is Lost Copyright © 2011 School of EECE, Newcastle University, Merz Court, Newcastle upon Tyne, NE1 7RU, United Kingdom Main contact for enquiries: Professor Alex Yakovlev, Telephone: (+44) 191 2228184, E-mail: [email protected] Copyright© 2011 School of 2 EECE, Newcastle University D.J.Kinniment Contents: Preface. The ability to choose Chapter 1. The rabbit in the headlights. The pilot’s dilemma What’s the problem? Chapter 2. Choice without preference. The way people think The history of Buridan’s Ass Aristotle The end of civilization The Arabs Chapter 3. The will of God. The medieval universities The disputation John Buridan and the early renaissance Freedom of the Will The Black Death Chapter 4 As long as it takes The mechanics of decisions The laws of motion Time and the pendulum Sorts of numbers Chapter 5 Kinds of infinity Harmony and rationality The music of the spheres Irrational numbers Newton and Leibniz The diagonal proof Copyright© 2011 School of 3 EECE, Newcastle University He Who Hesitates is Lost Chapter 6 Decisions at the speed of light Can it really take forever? Mechanics and electronics The birth of the baby Synchronous and asynchronous Ivor Catt Chapter 7 I don’t believe it Does it matter? The MU5 The buffer store The third world war It’s not over yet. Chapter 8 Beware the synchronizer System timing The tick of the clock Synchronization At the frontiers of timing Smaller and smaller, faster and faster A world without clocks Chapter 9. The casting of lots On a knife’s edge. The America presidential election November 2000 The throw of the dice. Thermal noise Noise in a synchronizer The ghost in the machine. Chapter 10 The Moral maze Making things simpler A matter of life or death. Copyright© 2011 School of 4 EECE, Newcastle University D.J.Kinniment Making the difference. Find the scapegoat Chapter 11 The Search for Certainty Understanding and simplicity Moral codes and what they do Trial by Jury Chapter 12 Four ways to beat Buridan. Don’t make choices if you don’t have to. Marge and the Elephant. The single track railway It’s a toss up Can I have my money back? Chapter 13 What philosophers think Choice and Free will Origination Fatalism and fortune telling The triumph of the will Chapter 14 Of men and machines Why there aren’t many starving donkeys Divide and conquer Abstraction and divisibility Them and us. Why people keep making the same mistake Can machines think? Copyright© 2011 School of 5 EECE, Newcastle University He Who Hesitates is Lost Preface. The ability to choose What is it that distinguishes people from machines? This question seems simple. Machines are mere inert collections of metal and plastic that simply respond to outside influences, push the accelerator, and the car goes faster, push the brake pedal, and it stops, whereas we believe that people have some internal quality that makes them individuals, and enables them to make choices for good or for evil. The concept that people have free will and consciousness, and machines do not is something that few question, but the more we try to explain what these ideas mean, the more difficult it seems to be to pin down any concrete notion that clearly distinguishes between men and machines. Machines do not appear to decide for themselves, but people do, machines are subject to outside forces, and the laws of nature, they have no soul, they are unable to make a moral choice. But what is this soul that allows people to make moral choices but not machines? Perhaps we should start, with the Greek philosophers, whose world was one of harmony, in which rational thought and whole numbers could explain everything. The earth was at the centre of the universe, and there was a simple relationship between the diameter and the circumference of a circle. For them, the reason that the earth stayed at the centre of everything was that it had no reason to do otherwise. If there was no reason to go to the edge of the universe why should it? In the middle ages concerns were more with the spiritual than the materialistic, God was the source of everything, but mankind was in some way special, so there was a need to understand this special relationship between God and Man. Men have immortal souls, but what about animals? Do animals have a soul? And if they do, do plants also have a soul, and so on down to the lowest form of single-celled life. Copyright© 2011 School of 6 EECE, Newcastle University D.J.Kinniment Why stop there? If a virus has a soul, why not a rock or a volcano? Volcanoes are not things you would want to annoy, they have in the past been worshipped as gods. What is animate and what is inanimate? This is a circular argument, where we just replace the words ‘having a soul’ with ‘animate’ and get no further. The debate in the middle ages centred on an apparent paradox called the paradox of Buridan’s Ass in which an Ass (an animal chosen apparently because of its obvious stupidity) is placed half way between two equally attractive bales of hay. Unfortunately it is unable to decide which one to eat first, and thus it starves to death. If its actions are purely determined by outside circumstances, like the placing of the bales of hay, their attractiveness, and so on, and past history, we can easily propose that there is nothing in these circumstances that inclines it one way or the other. So it starves, it is no better than a stone, which has no forethought for the future, no moral judgement, and no free will. But people have free will, they are not the slaves of circumstances and history, and can see that without making a choice between two food-laden tables, they might stay half way between and die. And it does seem possible in principle that a man might find himself in such a position. If he did, wouldn't he always find some way of choosing a table to go to first rather than let himself starve to death? `If I concede that he will [starve to death],' said Spinoza (1632 - 77), `I would seem to conceive an ass, or a statue of a man, not a man. But if I deny that he will, then he will determine himself, and consequently have the faculty of going where he wills and doing what he wills.' So what is this ‘differentiating principle’ or ‘origination’ that allows a man to choose one course or another when both seem equal in value? Is it something that originates in the soul, and allows a man to take a decision, which is in opposition to all of his history and his circumstances? Or is there no such thing, Copyright© 2011 School of 7 EECE, Newcastle University He Who Hesitates is Lost and we are all subject only to outside forces, history, our genes and the laws of physics? In short, is everything already determined? Computers seem to be the ultimate example of machines whose outputs are determined only by their inputs and the history of those inputs. They are expected to be thoroughly reliable and deterministic, and consequently are taking over many of the decisions that previously had been made by people, such as air traffic control, but in the 1960’s it became apparent that they were not as deterministic as we would like, and could make errors in an non-deterministic way. This turned out to be a fundamental problem, which cannot be avoided. It is not just associated with computers, but with the nature of decisions, and is associated with even the simplest mechanism asked to make an arbitrary choice. If both choices seem equally desirable how is the choice made? In the extreme, if the basis for a choice does not exist, either the machine cannot make it, or it is made on the basis of some internal quality innate in the machine and not dependant on outside influences. Since an arbiter in a computer is purely mechanical the problem of choice without preference could be observed and measured without the need to take account of humanity. The religious and philosophical implications were no longer relevant, and the results of the measurements made it clear that while it was not possible to get an exact balance of preference, as the balance became more equal the time taken for the choice increased without limit. More importantly, well before the donkey starved, random fluctuations in the decision making process would determine both the outcome, and the amount of time taken for a decision. Results like these seem difficult for people to accept. They hanker after ‘yes’, or ‘no’ rather than infinite variation in decision time, and certainty rather than the statistics of probability. Copyright© 2011 School of 8 EECE, Newcastle University D.J.Kinniment Even for computers, we cannot be absolutely certain that the results of a computation will be always be the same, machines are usually reliable and deterministic, given a set of inputs, the output can be predicted. The opposite is also true, the roll of dice cannot usually be predicted, but over many rolls of the same set of dice any bias in the weighting will become apparent. One number may come up more often than others. Machines are always partly deterministic, and partly non- deterministic.