For a brief history of free will, and a brief statement of why people people get so worked up about such an abstract subject, and a few words about why Community wiki people in particular find this important, see HistoryOfFreeWill.

"compatibilism": compatibility of determinism and moral choice / free will Wikipedia:compatibilism_and_incompatibilism

Not only do people argue about whether determinism is true or not, people argue about whether or not determinism is compatible with free will. Some people – “incompatibilists” – claim that determinism and free will are logically exclusive (incompatible); although they disagree on whether one or the other (or neither) is more likely to be true. Other people – “compatibilists” – claim that determinism and free will are not logically exclusive; although they may disagree about whether either one (or both) is more likely to be true.

… say something about “fatalism” here …

… is there a logical argument why people think they are compatible ? …

… is there a logical argument why people think they are incompatible ? …

science vs. opinion

Mapping the idea space is good. When the Greeks asked “atoms or not?”, they created a logical mapping on which science could act. And it took over 2000 years to get that from metaphysics into physics and decide the question. The experiments published by John Dalton in 1803, by Amedeo Avogadro in 1811, and by Albert Einstein in 1905, conclusively show that matter is composed of discrete units (“atoms”), rather than an arbitrarily divisible continuum.

Before those experiments, siding with “there must be atoms” or “there are no atoms” was not scientific, it was gambling. It would be gambling to side with “time-travel is possible” or “time-travel is impossible” today. If I say “time-travel is impossible” today and I’m proven right in 5000 years, I’m not proven a scientific genius, I’ve just taken chances.

The same is true for determinism vs. indeterminism now. So the mapping is valid science. Listing possible arguments and implications is science. However, taking a side is outside of science. Taking a side is a personal choice, an opinion.

As of 2007, no one really knows if the universe is strictly deterministic or not.

Some people who believe in determinism find it difficult to accept random processes as a intrinsic part of the universe, especially when the “evidence” for these processes can be explained in a deterministic way.

Both “belief in determinism” and “belief in non-deterministic free will” can get the character of religious beliefs. For a while, debates between these two ideas – between the Calvinists and the Armenians – actually were religious debates.


(See HistoryOfFreeWill)

In 1619, Johan van Oldenbarnevelt was beheaded because he supported the “wrong side” of the free will vs. determinism issue.

During the “Bohr-Einstein debates”, Einstein and others attempted to prove that the “Copenhagen interpretation” was incorrect. The most famous objection is the “EPR paradox”. (More on this later).

In 1957, Hugh Everett developed the “many-worlds interpretation” of quantum physics. Even more people don’t like the implications of the “many-worlds interpretation”. The implications of the “many-worlds interpretation” are widely regarded as absurd.

In 1974, Pier Giorgio Merli led researchers to perform the “one particle at a time” double-slit experiment for the first time. (More on this later).


There are a variety of valid interpretations of quantum mechanics. There are a huge number of misunderstandings, misconceptions, and misrepresentations of quantum mechanics. I hope we won’t need a QuantumMechanics page. “Quantum Fluctuations are the random nature of matter’s state of existence or nonexistence. At these incredibly small sub-atomic scales, the state of reality is fleeting, changing from nanosecond to nanosecond.” – Irregular Webcomic!

probability distribution

Wikipedia:Double-slit experiment

The 2 slit experiment involves a source of light, a mask with 2 rectangular slits, and a screen. Later experiments have shown similar results with electrons, individual ions, and some small molecules. Experimenters are now (as of 2007) attempting to diffract viruses.

We look at what appears on the screen. (Typically we run the experiment 3 times: once with only the left slit open, once with only the right slit open, and once with both slits open).

If we assume photons and electrons act like tiny bullets, we would expect some bullets to go in a straight line from the emitter, through the middle of the hole in the mask, to a specific point on the screen. We would expect all the bullets that hit the screen to make a single cluster around that point. (With a bit of scattering of the bullets that graze the edge of the hole in the mask). (When both slits are open, we expect the pattern to be the sum of the 2 patterns when either slit was open).

If we assume light and electron beams are made of waves, then we can calculate a diffraction pattern. The diffraction pattern is very different when both slits are open than when only one slit is open.

When we actually do the experiment, we get a diffraction pattern. So the “particle” theory is ruled out. Before 1974, the logical conclusion was that both electrons and photons are actually waves.

In 1974, Pier Giorgio Merli led researchers to perform the “one particle at a time” double-slit experiment for the first time. That first “one particle at a time” experiment used electrons.

During the experiment, the electron gun shot out one electron at a time. Sometimes nothing would happen (presumably the electron was absorbed by the mask); other times the electron would hit a single point on the screen, which would light up. Over time, some areas of the screen would get hit by a high density of points of light; other areas of the screen would get hardly any hits.

However, the impact points do not hit the screen in any predictable order. In other words, knowing where the last electron appeared on the screen tells us nothing about where the next electron will hit.

The electrons (and the same applies to photons and other small particles) hit points on the screen in an unpredictable sequence.

If you try to repeat the experiment, the particular sequence of points hit on the screen will be completely different. However, you get exactly the same probability distribution – an area that got hit by a high density of points in one experiment will get hit by a high density in the next experiment; an area that got hit by a low density in one experiment will get hit by a low density in the next experiment.

The information about where a particular electron will hit the screen – this information (apparently) spontaneously comes into existence out of nowhere – that information (apparently) simply does not exist in the initial condition, as if God waited until just that moment to make a decision.

Quantum mechanics can be used to predict that probability distribution very accurately. But it does not even try to predict what sequence of points on the screen will be hit.

Many people try to find out why each impact with the screen appears. They hope to find some reason, analogous to the way people have found reasons for real bullets to spread into a wide probability distribution pattern – minor differences in bullet imperfections, minor differences in the charge, differences in the wind, etc.

These “reasons” and “causes” are sometimes called “hidden variables”.

EPR paradox and Bell's theorem

the “EPR paradox”.

According to, Einstein, Podolsky and Rosen did not believe in the idea of genuine randomness in nature, and wrote a paper in 1934 claiming that quantum physics is “incomplete”, that there must be some sort of hidden information which determines the measurement outcome.

John Bell discovered that it was possible to build hardware that would demonstrate the EPR paradox.

In 1964, physicist John S. Bell stated Bell’s theorem: “No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics.” This theorem has even been called “the most profound in science.”

In other words, it is possible to build an experiment such that any “local hidden variable” theory would predict different results from quantum theory.

Such experiments (“Bell test experiments” ) were performed in A. Aspect in 1982; all such experiments to date give (within experimental precision) the results predicted by quantum theory.

So either

The Copenhagen interpretation of quantum mechanics is of the first type – it implies there is no such thing as a complete state information.

The Bohm interpretation of quantum mechanics is of the second type.

Alas, if the Bohm interpretation is correct, the hidden variables are communicated in a way that makes it impossible to send “information” faster than light. Only after the results have been noted and compared (using normal slower-then-light communication) are the weird correlations discovered.

Some skeptics have pointed out flaws in the 1982 experiments that don’t quite rule out all local hidden variable theories. Further experiments (most recently in 2007) have attempted to fix those flaws, ruling out more (but still not all) local hidden variable theories.

So what does this mean?

Our current habits of thinking and imagination are insufficient to cope with physics. People find it difficult to believe that

The more obscure predictions of physics are difficult to get in our head.

Some people believe that, while 4 dimensional space is difficult to picture, eventually (with practice) some people will be able to visualize it. We already know that many people find it difficult to visualize the way 3 dimensional mechanical parts fit together; but some people (with practice) eventually get pretty good at it.

But many people believe that quantum effects are so bizarre that no one will ever get an intuitive grasp on them.


People learn new things every day.

Every day, students in physics classes around the world unlearn things they thought were true.

Every year, mathematicians, physicists, and biologists comes up with an experiment to discriminate between two or more reasonable-sounding hypothesis. Before they run the experiment, all those hypothesis are “feasible” – as far as we know, any one of them (or possibly none of them) might be true, even though logically at most one of them can be true.

While designing the experiment, these people have to ask themselves “If this first hypothesis were true, what would happen?”, then ask themselves, “If this second hypothesis were true, what would happen?”, and try to set things up so the results are different.

The experiment rules out any hypothesis that predicts results that are different from what actually happened. Unfortunately, people sometimes make mistakes in reasoning. Sometimes these mistakes in reasoning about hypothesis lead to incorrect predictions that happen to disagree with the experiment, leading to pre-maturely rejecting out hypothesis. Sometimes these mistakes in reasoning about hypothesis lead to “incorrect” predictions that happen to agree with the experiment, leading the hypothesis being accepted when it should be rejected.

Such mistakes in reasoning are related to the “straw man” fallacy.

… say something about “defeasible reasoning” here …

Predictability, causality, and randomness

There is a spectrum between predictability and “truly random” non-causal events.

At one end we have things that are easily predictable using well-known techniques and a few pieces of easy-to-obtain information about the system. In many areas of physics, if you measure state of affairs to some given precision, you can predict what will happen centuries in the future to within about the same precision. For example, “When I let drop this ball, how long before it hits the ground?” can be answered roughly with a simple technique that only requires a few pieces of information, and fairly precisely with a more sophisticated technique that requires only a few more pieces of easy-to-obtain information. With only a few observations of a comet, its path can be predicted centuries in advance.

There are many things that are, in principle, predictable, but we have not yet developed techniques for predicting them. In particular, the people building particle accelerators and gravity wave telescopes hope to find objects that have never been observed before. Generally it takes a long time between when an object is first observed to the time that we come up with a good technique for predicting its behavior. The development of physics and the scientific revolution beginning around 1543 converted many of these situations to the “easily predictable” case.

Often there are things that are, in principle, predictable, but the information required to predict it is difficult to obtain. “Who is going to win this card game?” is easy to predict if you know who has which cards. Such situations are called “hidden knowledge” or “incomplete information”. A theory that assumes such information exits is called a “hidden variable theory”. After the game is over, it is easy to reconstruct who had which card, but that doesn’t help you in the middle of the game. Probability theory was developed around 1700 in order to deal with uncertainty generated by “passive” things like “measurement error” and dice. Game theory was developed in 1944 to deal with uncertainty generated by intelligent opponents.

… deterministic chaos …

At the opposite end of the spectrum are (hypothetical) events that happen “for no causal reason”. Such events are unpredictable, even if one were to (theoretically) have perfect knowledge of the situation leading up to the events.

complexity does not require nondeterministic randomness

A few simple, deterministic rules, operating on a very simple initial state, can lead to “infinite complexity” (Wikipedia:Fractal).

Many deterministic situations have “deterministic chaos”. For example, weather prediction running on a digital computer.

There is chaos everywhere in nature, which leads to (what is shorthanded to) “randomness”. But that doesn’t mean it’s non-deterministic underneath.


Does the universe have a non-causal component? Or was it predetermined from the big bang that Lion and giraffes would exist on a planet Earth?

Is there a truly random component in the universe, leading to non-causal events?

According some interpretations of quantum physics, yes. If these interpretations are correct, things happen for no causal reason.

… radioactive decay …

For a while, it seemed that such “truly random” events were extremely rare, and never happened inside the human body – and so could have nothing to do with intelligence or free will.

However, some interpretations of quantum theory imply that such “truly random” events happen all the time:

… reflection off a half-silvered mirror …

Is this kind of randomness necessary for intelligence or necessary for free will? (With the debatable exception that game theory shows “unpredictability” is useful as part of the optimum strategy in certain games…)

various meanings of "random"

People use the term “random” in a variety of ways. Sometimes we use “random” in situations that are completely deterministic, such as rolling of a roulette wheel. As soon as dealer lets go of the ball, one can predict precisely which pocket the ball will go into with a sufficiently accurate measurement of the speed of the wheel and the speed of the ball. But people still say it is “random”, because it is difficult to predict. When we carry in instruments to measure the speed and position of the roulette wheel and ball, the casino operators throw us out.

“The Nature of the Universe Great Debate in 1998”

not entirely random numbers

If there are trends and tendencies within the random numbers, we need to be careful – there may be laws governing the probabilities. The laws may make the probabilities deterministic (just as the chance of rolling snake-eyes is a deterministic 1/36), even though today’s random number may not be deterministic.



I had hoped to bring up Wikipedia:Newcomb's_paradox

Robert Nozick 1969 noted that “To almost everyone, it is perfectly clear and obvious what should be done. The difficulty is that these people seem to divide almost evenly on the problem, with large numbers thinking that the opposing half is just being silly.”

Some people believe this thought experiment shows that free will and determinism are incompatible, using “proof by contradiction”.

Yes, but let’s step back a bit and separate the high-level strategy from the low-level implementation. Instead of having a human being directly grab box A or box B, imagine that we put him in a remote location, where he can receive a message by teletype “you are going to pick A”, and then he can push the big A button or the big B button. … Let’s go further, and let the human describe his strategy and embed it into a simple circuit: … … … the predictor models the circuit … and something very interesting happens when the we connect the “contrary” circuit up to the “predictor” circuit with its light bulb; …

Wikipedia:Kavka's_toxin_puzzle speaks even more directly about free will.

free will

What is “free will”? There are a variety of concepts associated with “free will”. Quite a few of them are misunderstandings.

Too many explanations of free will make no sense. But then, too many explanations of calculus make no sense, either.

Is it something that is neither random, nor determined?

Some “proofs” of free will rely on a straw-man fallacy, building on myths about determinism (we’ll go into those more later).

… (need more here) …

The “open theism” people emphasize free will. They claim that not even God knows every detail of what will happen in the future – in particular, prayer influences God. They claim that no-one (not even God) can predict the exact form of an ocean wave at a specific point in time and space an hour from now.

“What would Free Will mean?”

If we were to pull back time, 30 seconds into the past, and then have a fresh go at things – Would it mean that you would do anything different? If so, Why?

What would it mean in terms of justice system, in terms of thoughts, in terms of anything, for “Free Will”, whatever it is supposed to mean, (and please explain to me what it means,) to be true?

Can I really “bend reality, shaping it to my will” ?

Can I really “reject your reality, and substitute my own” (– Wikipedia:Adam_Savage) ?

… …

Humans seem to have an intuitive understanding of free will, but putting a definition into words is difficult. Much like humans have an intuitive understanding of how to walk, but it took decades of robotics research to build a biped. Much like humans have an intuitive understanding of how to decode spoken speech into written words, but it took decades of research to build speech-to-text translators, and there is still quite a ways to go.

Hopefully an approximate definition plus a few clarifying examples will be adequate for this page:

Approximate definition of “free will”: a conscious decision that has long-term guiding effects that can neither be predetermined nor causally influenced.

Another approximate definition of “free will”: When circumstances allow several possible courses of action, “free will” is a conscious decision to choose one of them.

Another approximate definition of “free will”: When circumstances allow several possible courses of action, “free will” is a conscious decision to choose one guided by one’s beliefs, desires, and character, without external coercion.

A few clarifying examples:

An air conditioning system makes decisions about turning cooling on and off. But it doesn’t have “free will”.

A “decision” occurs at a point in time. But “will” has a duration. For example, a decision like “buy X” is not an example of free will, while “stop smoking” or “sticking to a diet” might be.

In philosophy, the problem of “free will” is an old one. There has been much speculation over the centuries, but we don’t have even the beginnings of a solution. One’s beliefs on determinism/indeterminism influences how one can think about free will.

… (need even more here) …


Many people believe “determinism”. Determinism means “The universe has state, and the succeeding states follow immediately from prior states.” In other words, “The state at some instant of time in the future is a function of only the state at the present”. Or in other words, “Given the same initial situation twice, the results will be the same both times.”

The vast majority of the observable universe at least appears to be deterministic.

… say something about “causality” here …

… is “determinism” exactly the same as “belief that causality is never violated” ? …

There are a few common misconceptions of what determinism is or what it implies:

Determinists believe that people make choices, decisions, and selecting the future.

“Choice” and “making a decision” are excellent names (and I challenge anyone to show otherwise) for “when your brain takes a collection according to the deterministic laws of molecules and atoms and thoughts and chemicals and cells and neurons and so on.”

Please read the Wikipedia article on determinism (Wikipedia:determinism).

It is a popular misconception that determinism necessarily entails that humanity or individual humans have no influence on the future and its events (a position known as Fatalism). Determinists believe that the level to which human beings have influence over their future is itself dependent on the present and past. Causal determinism is associated with, and relies upon, the ideas of Materialism and Causality. Some of the philosophers who have dealt with this issue are William James, Pierre-Simon Laplace, Arthur Schopenhauer, Omar Khayyám, David Hume, Thomas Hobbes, Immanuel Kant, Paul Henri Thiry, Baron d’Holbach and, more recently, John Searle and Ted Honderich.

Determinism does not mean “predictable”. Computers are completely deterministic. Consider an enormously large computer program, or a vast computer network, all parts operating in clockwork. The inability to predict is a martial field where people struggle to just keep computers running, and regularly do battle with computer viruses.

Determinism does not mean “simple behavior”. Conway’s Game of Life (Wikipedia:Conway%27s_Game_of_Life) has a very simple set of rules and a completely deterministic system. Yet it is capable of exhibiting quite complicated behaviors.

There are a few things that don’t seem to follow immediately from prior state, such as radioactive decay and free will. Given apparently the same situation, people with free will will not always make the same choice. Given apparently the same situation, some atoms will decay within seconds, while other apparently identical atoms of the same element in apparently the same environment will delay for decades before decaying.

So are these things really non-deterministic? Or is there some subtle “hidden information”, slight differences – either inside the atoms or in their environment – that would explain the differences in the results?

Currently we don’t know. We can predict the results of many situations very accurately using quantum physics. In some situations, quantum physics accurately predicts that 8% of the time we will see one result, and 92% of the time we will see the other result.

According to Wikipedia:interpretation of quantum mechanics ( ) , people hold a variety of interpretations of quantum mechanics, all of which predict exactly the same results from any given experiment (and hence, unfortunately, it is impossible to use experiments to find which interpretation is the “right” interpretation).

Some of those interpretation of quantum mechanics are deterministic, and some are not.

If the universe is deterministic, then any closed system is, in principle, completely predictable, if we only had complete state information. However, there are 3 reasons why closed systems are usually not, in practice, completely predictable by human beings:

The Heisenberg uncertainty principle seems to indicate that (2) will always be the case. It implies that there is some maximum amount of information we can have about an atom. It implies that any attempt to gain more information about its momentum (or to force its momentum closer to some pre-determined value) inevitably leads to a loss of information about its position.

It may turn out that the universe is not completely deterministic after all, leading to a fourth reason why closed systems are not completely predictable:

determinism vs. choice

We all agree that people clearly make choices. We all agree that those choices clearly influence the future.

And so we all agree that any theory that concludes that people don’t make choices, as well as any theory that concludes that our choices have no influence on the future, can be rejected.

A determinist would say: brains make choices every day, but it does not require randomness to do so. Determinists explain the choices people make in terms of brain processes. Most (but not all) people who study the brain assume that these processes operate entirely deterministically. When a person is making a choice, there is a scurrying of atoms, molecules, neurons, electrical impulses, and thoughts and so on, within the brain, whenever there is an agitated state of dilemma within the mind. The brain quickly searches, does a lot of prediction scenarios, performs a whole bunch of other things, chemicals flying back and forth, and so on; it’s trying to figure out what to do.

Ah. A solution comes.

The brain settles on one possibility, and one course of action. The activity in the brain comes to a close. It has made a choice.

If “making a choice” is not the right word for that agitation, and “made a choice” is not the right word for the end of that agitation, what words should we use?

Even the earliest computers (generally accepted to operate deterministically) can easily be said to make choices, even complex choices. Before it’s made a decision, it hasn’t made it’s choice. After it’s made it’s decision, it has made a choice. How did it make a choice? What does it mean for it to make a choice? It goes through all it’s inputs, looks at all the various weights, participates in any number of evolutionary, or connectionist, or algorithmic processes, and then decides: the caches flush, the queries cease, the answer provided.

Determinists would say those choices partially “determine” the future. “Partially”, because there are so many agents in the world, that one agent only has so much influence on the outcome of events. But, all people, all universe taken together, (plus any random cosmic number generators in existence, should we be talking Determinism Plus,) completely determine the outcome.

If determinists are correct, then deterministic artificial intelligences will be perfectly capable of making decisions, and making choices.

is it dangerous to believe people don't have free will

Please note that there is a huge difference between a person failing to use some ability vs. a person who does not understand some ability.

I think we all agree that humans really do have amazing amounts of creativity and the ability to do great things and build incredible artifacts. And we all agree that it would be a shame if people stopped doing this because they were deluded into (incorrectly) thinking that it was impossible to do such things.

When a person does not understand how blood flows through his body, that doesn’t stop the blood from flowing. Even when a person believes in a incorrect understanding of how the blood flows, the blood still flows correctly through his body.

Is the same true of free will – people can still use it, whether they understand it correctly or not? Or is there some danger that incorrect understanding of free will would lead to bad things? We certainly don’t want to repeat the unfortunate events of the past, such as the incorrect understanding of the mental capacity of certain groups of people led to inadequate training (“He’ll never understand this, so why bother trying to teach it?”) with the resulting inadequate education perpetuating the myth.

If people think humans are completely deterministic, then some people may be tempted to develop technologies to manipulate humans, to try to “reset” their state to one that results in doing what I want.

If people think humans are, even in principle, uncontrollable, then perhaps those people won’t even try to develop such manipulation technologies.

determinism plus

“determinism plus” is the idea that the universe has state, that succeeding states follow as a function of the previous state plus some completely random components.

We can point to exactly the place in the function where “and a non-deterministic, completely random number goes here”.

“determinism plus” alone does not adequately explain “free will”.


Most inanimate objects are obviously deterministic. For example, the wrench accidentally left in low earth orbit. That wrench will continue to orbit the earth indefinitely in the same orbit, until something hits it and changes its orbit. That orbit is completely predictable from a few external photographs of its position and velocity.

A few inanimate objects (and all living things) have “internal state”. When I see them moving down the road, I have no way to tell from any number of external photographs whether or not they know that the left fork is a useless dead-end, and the right fork is the best way to go.

… determinism does not mean “no internal state” …

ethics with pure determinism

“If it’s atoms and molecules, and if the universe “already knows” what will come out, how can I be making choices?”

You’ve been given a brain. That brain makes choices. What more do you want?

If someone steals candy at the grocery store, but that is the direct result of material forces set in motion at the beginning of time, long before that person was even born, in what sense is it that person’s fault?

How can we ethically build a justice system? What is the SourceOfEthics?

Some people (the anti-deterministic Free-Will-ers) apparently believe that you cannot jail a person, if it’s not ultimately the fault of that person. This is absurd. If someone is going to destroy things or kill people, then that person must be restrained, whether or not it is “their fault”.

A time bomb clearly has no free will, and yet it must also be stopped – even though we all agree that it’s not “its fault” that it will detonate.

At this level, is not a question of blame and justice, it is a question of martial security.

Perhaps coming to a correct understanding of what it means to be human will lead to a better justice system. If we know more about the cause of crime and recidivism, perhaps we could do a better job reforming and retraining, making adjustments to the national system, other people, and myself, and then we would need less less imprisoning.

What about God judging people? It seems unfair that he would throw men into heaven or hell based on their actions, when he knew millennia ago the forces set in motion would inevitably determine those actions, and there is nothing those men could do to stop those actions.

ethics with determinism + randomness

The ethical situation with determinism + randomness may be even worse than determinism alone.

And why do some people think it makes a difference whether they roll their own dice, or someone else rolls their dice for them?

spiritual choice

Whether or not there is a spiritual system has no bearing on the questions of free will and determinism.

Some people think that, if there is a spiritual world, it means that determinism is not true.

We agree that, if there is a spiritual world, then certainly events in the material world today are not entirely determined by the state of the material world yesterday.

But we have to ask: if your spirit or soul makes decisions, how does it do that? Does it make decisions based on what came before? Or does it just pick a random number?

How does the Soul understand and make decisions? Does it have a mind? Is it just random? Why should we dialog: How could dialog influence the soul? Will it make different decisions given the exact same circumstance? Based on what?

All our ideas about what a soul is, or how a soul works, are based on a deterministic (or deterministic plus random) explanation. Either way, we still have the same ethical problems with determinism or determinism plus randomness.

criticism of determinism

Humans have an unconscious bias towards causal explanations of events, even when the events are actually random. We want to believe that things happen because they are part of an intelligent “master plan”.

So we should not be too quick to rule out the possibility that events are actually non-causal.

The assumption of strict causality acts like blinkers restricting what one can see.

“Of the 32 possible sequences resulting from six coin flips, few actually look “random.” This is because randomness is a property of the process that generates the data that are produced. Randomness may in some cases be demonstrated by scientific (statistical) analysis. However, events will almost never be perceived intuitively as being random; one can find an apparent pattern in almost any set of data or create a coherent narrative from any set of events. Because of a need to impose order on their environment, people seek and often believe they find causes for what are actually random phenomena. During World War II, Londoners advanced a variety of causal explanations for the pattern of German bombing. Such explanations frequently guided their decisions about where to live and when to take refuge in air raid shelters. Postwar examination, however, determined that the clustering of bomb hits was close to a random distribution.” -- "Biases in Perception of Cause and Effect"

… (needs more here) …

However, there is an easy way of seeing if these causal explanations are real or just wishful thinking: “Can it predict?” If it can’t, then that explanation is useless.

One positive point about indeterminism is, that it is more tolerant. If we assume that sometimes things happen that can’t be predicted, then we won’t be as surprised when, in fact, things don’t go as predicted.

When an enemy sniper uses the roll of a dice to randomly pick one of six soldiers to shoot, it is unfair to assume that the wounded soldier “must have done something wrong”, and then praise the 5 other solders for being good at finding cover and blame the wounded soldier for being bad at finding cover.

If we assume that every situation is deterministic, then we may waste far too much time and effort obsessively trying to discover the real reason something happened -- or worse, give up too soon with an (incorrect) reason something happened.

“Assuming that a foreign government’s actions result from a logical and centrally directed plan leads an analyst to:

-- "Biases in Perception of Cause and Effect"

If we assume determinism, then we assume that the result is predictable – but some situations (especially in politics) are humanly unpredictable.

If we assume that a human or a nation is completely deterministic, it is all too easy to assume that we can merely list all possible ways we can push them, analyze the deterministic outcome, and then pick the kind of push that can push them out of their current “imperfect” state into a specific “desirable” state.

Our assumption of a causal-mechanistic paradigm led to the conclusion that the type of push we selected is guaranteed to have the predicted effect. But this neglects the fact that the harder we push a human or a nation, the more likely that there will be an unwanted and unpredictable reaction.

It would have been much more helpful to understand that a complex system like a state is in principle unpredictable, and that there is the risk of failure.

We are rapidly learning more and more about parts of the brain – the molecules involved, the axons, the dendrites, etc. But we do not know how the brain is working as a system. We don’t even know simple things like how a line of a poem is stored and remembered. We also do not know how consciousness comes about, what it is. So neuro-science is at the very beginning. Some suspect that the causal-analytical-mechanical model of science hinders progress in this field.

criticism of free will

Humans also have an unconscious bias towards seeing actions as the result of centralized direction and rational goal-maximizing planning, even when they are actually the results of confusion, vacillation, blunder, unintended consequences of well-intentioned policy, and coincidences.

“people are slow to perceive accidents, unintended consequences, coincidences, and small causes leading to large effects. Instead, coordinated actions, plans and conspiracies are seen. … overestimate the extent to which other countries are pursuing coherent, rational, goal-maximizing policies, because this makes for more coherent, logical, rational explanations.” -- "Biases in Perception of Cause and Effect"

… (needs more here) …

An important part of the NatureOfScience is asking the questions “Why?”, and hoping that there is some answer. When people dismiss that “Why?” with “It’s just random”, or “He did that because he wanted to”, is the same as saying “Don’t bother looking for a reason”.

To do science, we must at least suspect that the process under observation is deterministic. We can’t merely say “It’s just random” or “it’s the will of the gods” and not even try to find a better explanation.

various deterministic viewpoints

Wikipedia:determinism shows there are various philosophical viewpoints about the possible connections of determinism and free will, and all are considered possible viewpoints.


Some interpretations of quantum physics predict a kind of physical random noise in empty space (gluon fluctuations). This noise makes small interactions somewhat unpredictable. In most situations, macro events depend only on the average of a large number of small interactions. The random noise almost entirely “cancels out” over such large number of interactions, and so the random noise has almost no influence on normal macro events.

However, this “random noise” makes humans and the universe itself unpredictable in the long run.

(But then, deterministic chaos also makes humans and the universe itself unpredictable in some ways in the long run).

predicting failure

“a nice task for predictors … would be to predict when (exact point in time) a clockwork will stop working.”

… “crack propagation theory” …

further reading