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❶Broad, "Indeterminism is the doctrine that some, and it may be all, events are not completely determined. In one sense this is a philosopher's nightmare:


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Jonathan Lowe John R. Kastner Stuart Kauffman Martin J. Determinism is the philosophical idea that every event or state of affairs, including every human decision and action, is the inevitable and necessary consequence of antecedent states of affairs. More strictly, determinism should be distinguished from pre-determinism , the idea that the entire past as well as the future was determined at the origin of the universe.

Nor should determinism be confused with determination , the idea that events including human actions can be adequately determined by immediately prior events such as an agent's reasons, motives, desires , without being pre -determined back to before the agent's birth or even back to the origin of the universe.

Since modern quantum physics shows that the universe is indeterministic , with profound effects on microscopic processes at the atomic scale, we will find it valuable to distinguish pre -determinism from the adequate determinism that we have in the real world.

Adequate determinism is the basis for the classical physical laws that apply in the macrocosmos. Determinism is a modern name coined in the nineteenth-century for Democritus ' ancient idea that causal deterministic laws control the motion of atoms, and that everything - including human minds - consists merely of atoms in a void.

As Democritus' mentor and fellow materialist Leucippus put it, an absolute necessity leaves no room in the cosmos for chance. William James or compatibilism , is supported as a theory of free will by a majority of philosophers, each with special vested interests in one or more of the many determinisms.

Compatibilists accept determinism but argue that man is free as long as his own will is one of the steps in the causal chain, even if his choices are completely predetermined for physical reasons or preordained by God. And Fatalism is a special form of determinism where every event in the future is fated to happen.

Fatalism does not normally require that any causal laws or higher powers are involved. The core idea of determinism is closely related to the idea of causality. But we can have causality without determinism, especially the "soft" causality that follows an "uncaused" event a causa sui that is not predictable from prior events.

Despite David Hume 's critical attack on the necessity of causes, many philosophers embrace causality and determinism strongly. Some even connect it to the very possibility of logic and reason. And Hume himself believed strongly, if inconsistently, in necessity. Bertrand Russell said "The law of causation, according to which later events can theoretically be predicted by means of earlier events, has often been held to be a priori , a necessity of thought, a category without which science would not be possible.

But it does not. Indeterminism for some is simply an occasional event without a cause. We can have an adequate causality without strict determinism. Strict determinism means complete predictability in principle, if not in practice of events and only one possible future. Adequate determinism provides statistical predictability, which in normal situations for physical objects approaches statistical certainty.

An example of an event that is not strictly caused is one that depends on chance , like the flip of a coin. If the outcome is only probable, not certain, then the event can be said to have been caused by the coin flip, but the head or tails result itself was not predictable.

So this causality, which recognizes prior events as causes, is undetermined and the result of chance alone. We call this "soft" causality. Events are caused by prior uncaused events, but not determined by events earlier in the causal chain, which has been broken by the uncaused cause.

Determinism is critical for the question of free will. Strict determinism implies just one possible future. Chance means that the future is unpredictable. Chance allows alternative futures and the question becomes how the one actual present is realized from these alternative possibilities.

The departure required from strict determinism is very slight compared to the miraculous ideas associated with the " causa sui " self-caused cause of the ancients. Even in a world that contains quantum uncertainty, macroscopic objects are determined to an extraordinary degree.

But the macroscopic "laws of nature" are just statistical laws that " emerge " when large numbers of atoms or molecules get together. For large enough numbers, the probabilistic laws approach practical certainty. Determinism is an emergent property. Newton's laws of motion are deterministic enough to send men to the moon and back. Our Cogito Model of the Macro Mind is large enough to ignore quantum uncertainty for the purpose of the reasoning will.

The neural system is robust enough to insure that mental decisions are reliably transmitted to our limbs. We call this determinism, only ineffective for extremely small structures, "adequate determinism. Belief in strict determinism, in the face of physical evidence for indeterminism, is only tenable today for dogmatic philosophy. We survey ten modern dogmas of determinism. Phillipa Foot argued that because our actions are determined by our motives, our character and values, our feelings and desires, in no way leads to the conclusion that they are pre -determined from the beginning of the universe.

The presence of quantum uncertainty leads some philosophers to call the world indetermined. But indeterminism is somewhat misleading, with strong negative connotations, when most events are overwhelmingly " adequately determined. There is also no problem imagining a role for randomness in the brain in the form of quantum level noise. Noise can introduce random errors into stored memories.

Noise could create random associations of ideas during memory recall. This randomness may be driven by microscopic fluctuations that are amplified to the macroscopic level. Our Macro Mind needs the Micro Mind for the free action items and thoughts in an Agenda of alternative possibilities to be de-liberated by the will. It may well be true that there are some deterministic dynamical systems that, when viewed properly , display behavior indistinguishable from that of a genuinely stochastic process.

For example, using the billiard table above, if one divides its surface into quadrants and looks at which quadrant the ball is in at second intervals, the resulting sequence is no doubt highly random. But this does not mean that the same system, when viewed in a different way perhaps at a higher degree of precision does not cease to look random and instead betray its deterministic nature. If we partition our billiard table into squares 2 centimeters a side and look at which quadrant the ball is in at.

And finally, of course, if we simply look at the billiard table with our eyes, and see it as a billiard table , there is no obvious way at all to maintain that it may be a truly random process rather than a deterministic dynamical system. See Winnie for a nice technical and philosophical discussion of these issues.

Winnie explicates Ornstein's and others' results in some detail, and disputes Suppes' philosophical conclusions. It is natural to wonder whether chaotic behavior carries over into the realm of systems governed by quantum mechanics as well.

Interestingly, it is much harder to find natural correlates of classical chaotic behavior in true quantum systems see Gutzwiller Some, at least, of the interpretive difficulties of quantum mechanics would have to be resolved before a meaningful assessment of chaos in quantum mechanics could be achieved.

The popularization of chaos theory in the relatively recent past perhaps made it seem self-evident that nature is full of genuinely chaotic systems.

In fact, it is far from self-evident that such systems exist, other than in an approximate sense. Nevertheless, the mathematical exploration of chaos in dynamical systems helps us to understand some of the pitfalls that may attend our efforts to know whether our world is genuinely deterministic or not. Is there nothing left that could sway our belief toward or against determinism?

There is, of course: Metaphysical arguments on this issue are not currently very popular. But philosophical fashions change at least twice a century, and grand systemic metaphysics of the Leibnizian sort might one day come back into favor.

Conversely, the anti-systemic, anti-fundamentalist metaphysics propounded by Cartwright might also come to predominate. As likely as not, for the foreseeable future metaphysical argument may be just as good a basis on which to discuss determinism's prospects as any arguments from mathematics or physics. John Earman's Primer on Determinism remains the richest storehouse of information on the truth or falsity of determinism in various physical theories, from classical mechanics to quantum mechanics and general relativity.

Here I will give only a brief discussion of some key issues, referring the reader to Earman and other resources for more detail. Figuring out whether well-established theories are deterministic or not or to what extent, if they fall only a bit short does not do much to help us know whether our world is really governed by deterministic laws; all our current best theories, including General Relativity and the Standard Model of particle physics, are too flawed and ill-understood to be mistaken for anything close to a Final Theory.

Nevertheless, as Earman stressed, the exploration is very valuable because of the way it enriches our understanding of the richness and complexity of determinism.

Despite the common belief that classical mechanics the theory that inspired Laplace in his articulation of determinism is perfectly deterministic, in fact the theory is rife with possibilities for determinism to break down. One class of problems arises due to the absence of an upper bound on the velocities of moving objects. Below we see the trajectory of an object that is accelerated unboundedly, its velocity becoming in effect infinite in a finite time.

An object accelerates so as to reach spatial infinity in a finite time. Never mind how the object gets accelerated in this way; there are mechanisms that are perfectly consistent with classical mechanics that can do the job. In fact, Xia showed that such acceleration can be accomplished by gravitational forces from only 5 finite objects, without collisions.

No mechanism is shown in these diagrams. But now recall that classical mechanics is time-symmetric: Clearly, a world with a space invader does fail to be deterministic. A second class of determinism-breaking models can be constructed on the basis of collision phenomena. The first problem is that of multiple-particle collisions for which Newtonian particle mechanics simply does not have a prescription for what happens.

Consider three identical point-particles approaching each other at degree angles and colliding simultaneously. That they bounce back along their approach trajectories is possible; but it is equally possible for them to bounce in other directions again with degree angles between their paths , so long as momentum conservation is respected. Moreover, there is a burgeoning literature of physical or quasi-physical systems, usually set in the context of classical physics, that carry out supertasks see Earman and Norton and the entry on supertasks for a review.

A failure of CM to dictate a well-defined result can then be seen as a failure of determinism. In supertasks, one frequently encounters infinite numbers of particles, infinite or unbounded mass densities, and other dubious infinitary phenomena. Coupled with some of the other breakdowns of determinism in CM, one begins to get a sense that most, if not all, breakdowns of determinism rely on some combination of the following set of physically dubious mathematical notions: The trouble is, it is difficult to imagine any recognizable physics much less CM that eschews everything in the set.

A ball may spontaneously start sliding down this dome, with no violation of Newton's laws. Reproduced courtesy of John D.

Norton and Philosopher's Imprint. Finally, an elegant example of apparent violation of determinism in classical physics has been created by John Norton As illustrated in Figure 4 , imagine a ball sitting at the apex of a frictionless dome whose equation is specified as a function of radial distance from the apex point.

This rest-state is our initial condition for the system; what should its future behavior be? Clearly one solution is for the ball to remain at rest at the apex indefinitely. But curiously, this is not the only solution under standard Newtonian laws. The ball may also start into motion sliding down the dome—at any moment in time, and in any radial direction.

And it does not, unlike some supertask examples, require an infinity of particles. Still, many philosophers are uncomfortable with the moral Norton draws from his dome example, and point out reasons for questioning the dome's status as a Newtonian system see e. Two features of special relativistic physics make it perhaps the most hospitable environment for determinism of any major theoretical context: The former feature, including a prohibition against tachyons hypothetical particles travelling faster than light [ 4 ] , rules out space invaders and other unbounded-velocity systems.

The latter feature makes the space-time itself nice and stable and non-singular—unlike the dynamic space-time of General Relativity, as we shall see below. For source-free electromagnetic fields in special-relativistic space-time, a nice form of Laplacean determinism is provable. Unfortunately, interesting physics needs more than source-free electromagnetic fields. IV surveys in depth the pitfalls for determinism that arise once things are allowed to get more interesting e.

Defining an appropriate form of determinism for the context of general relativistic physics is extremely difficult, due to both foundational interpretive issues and the plethora of weirdly-shaped space-time models allowed by the theory's field equations. The simplest way of treating the issue of determinism in GTR would be to state flatly: Here we will briefly describe some of the most important challenges that arise for determinism, directing the reader yet again to Earman , and also Earman for more depth.

What is the further structure a space-time needs? Typically, at least, we expect the time-direction to be distinguished from space-directions; and we expect there to be well-defined distances between distinct points; and also a determinate geometry making certain continuous paths in M be straight lines, etc. All of this extra structure is coded into g , the metric field. So M and g together represent space-time. T represents the matter and energy content distributed around in space-time if any, of course.

Yet, the new model is also a perfectly valid model of the theory. This looks on the face of it like a form of indeterminism: GTR's equations do not specify how things will be distributed in space-time in the future, even when the past before a given time t is held fixed.

Usually the shift is confined to a finite region called the hole for historical reasons. This is a form of indeterminism first highlighted by Earman and Norton as an interpretive philosophical difficulty for realism about GTR's description of the world, especially the point manifold M. See the hole argument and Hoefer for one response on behalf of the space-time realist, and discussion of other responses.

For now, we will simply note that this indeterminism, unlike most others we are discussing in this section, is empirically undetectable: The separation of space-time structures into manifold and metric or connection facilitates mathematical clarity in many ways, but also opens up Pandora's box when it comes to determinism.

The indeterminism of the Earman and Norton hole argument is only the tip of the iceberg; singularities make up much of the rest of the berg. For example, near the center of a Schwarzschild black hole, curvature increases without bound, and at the center itself it is undefined, which means that Einstein's equations cannot be said to hold, which means arguably that this point does not exist as a part of the space-time at all!

Some specific examples are clear, but giving a general definition of a singularity, like defining determinism itself in GTR, is a vexed issue see Earman for an extended treatment; Callender and Hoefer gives a brief overview.

We will not attempt here to catalog the various definitions and types of singularity. Different types of singularity bring different types of threat to determinism. Generally, no violation of determinism looms outside the event horizon; but what about inside?

Another way for a model spacetime to be singular is to have points or regions go missing, in some cases by simple excision. The resulting spacetime satisfies Einstein's equations; but, unfortunately for any inhabitants, the universe comes to a sudden and unpredictable end at time E.

For discussion of precise versions of such a requirement, and whether they succeed in eliminating unwanted singularities, see Earman , chapter 2. The most problematic kinds of singularities, in terms of determinism, are naked singularities singularities not hidden behind an event horizon. When a singularity forms from gravitational collapse, the usual model of such a process involves the formation of an event horizon i.

A universe with an ordinary black hole has a singularity, but as noted above, outside the event horizon at least nothing unpredictable happens as a result. A naked singularity, by contrast, has no such protective barrier. In much the way that anything can disappear by falling into an excised-region singularity, or appear out of a white hole white holes themselves are, in fact, technically naked singularities , there is the worry that anything at all could pop out of a naked singularity, without warning hence, violating determinism en passant.

While most white hole models have Cauchy surfaces and are thus arguably deterministic, other naked singularity models lack this property. Physicists disturbed by the unpredictable potentialities of such singularities have worked to try to prove various cosmic censorship hypotheses that show—under hopefully plausible physical assumptions—that such things do not arise by stellar collapse in GTR and hence are not liable to come into existence in our world.

To date no very general and convincing forms of the hypothesis have been proven, so the prospects for determinism in GTR as a mathematical theory do not look terribly good. As indicated above, QM is widely thought to be a strongly non-deterministic theory. Popular belief even among most physicists holds that phenomena such as radioactive decay, photon emission and absorption, and many others are such that only a probabilistic description of them can be given.

The theory does not say what happens in a given case, but only says what the probabilities of various results are. So, for example, according to QM the fullest description possible of a radium atom or a chunk of radium, for that matter , does not suffice to determine when a given atom will decay, nor how many atoms in the chunk will have decayed at any given time. The theory gives only the probabilities for a decay or a number of decays to happen within a given span of time.

Einstein and others perhaps thought that this was a defect of the theory that should eventually be removed, by a supplemental hidden variable theory [ 6 ] that restores determinism; but subsequent work showed that no such hidden variables account could exist. At the microscopic level the world is ultimately mysterious and chancy. Ironically, quantum mechanics is one of the best prospects for a genuinely deterministic theory in modern times!

Everything hinges on what interpretational and philosophical decisions one adopts. The evolution of a wavefunction describing a physical system under this equation is normally taken to be perfectly deterministic. There are several interpretations that physicists and philosophers have given of QM which go this way. See the entry on quantum mechanics. The collapse process is usually postulated to be indeterministic, with probabilities for various outcomes, via Born's rule, calculable on the basis of a system's wavefunction.

The once-standard Copenhagen interpretation of QM posits such a collapse. The reason is simple: In David Bohm created an alternative interpretation of non relativistic QM—perhaps better thought of as an alternative theory—that realizes Einstein's dream of a hidden variable theory, restoring determinism and definiteness to micro-reality.

In Bohmian quantum mechanics , unlike other interpretations, it is postulated that all particles have, at all times, a definite position and velocity. As much as any classical theory of point particles moving under force fields, then, Bohm's theory is deterministic. In one sense this is a philosopher's nightmare: Fortunately, we can safely assume that neither is perfectly correct, and hope that our Final Theory has no such empirically equivalent rivals.

In other senses, the Bohm theory is a philosopher's dream come true, eliminating much but not all of the weirdness of standard QM and restoring determinism to the physics of atoms and photons. The interested reader can find out more from the link above, and references therein. This small survey of determinism's status in some prominent physical theories, as indicated above, does not really tell us anything about whether determinism is true of our world.

Instead, it raises a couple of further disturbing possibilities for the time when we do have the Final Theory before us if such time ever comes: Second, we may have reason to worry that the Final Theory, if indeterministic, has an empirically equivalent yet deterministic rival as illustrated by Bohmian quantum mechanics.

Some philosophers maintain that if determinism holds in our world, then there are no objective chances in our world. Non-trivial probabilities are probabilities strictly between zero and one. Conversely, it is often held, if there are laws of nature that are irreducibly probabilistic, determinism must be false.

Some philosophers would go on to add that such irreducibly probabilistic laws are the basis of whatever genuine objective chances obtain in our world. The discussion of quantum mechanics in section 4 shows that it may be difficult to know whether a physical theory postulates genuinely irreducible probabilistic laws or not.

If a Bohmian version of QM is correct, then the probabilities dictated by the Born rule are not irreducible. If that is the case, should we say that the probabilities dictated by quantum mechanics are not objective? The first option may seem hard to swallow, given the many-decimal-place accuracy with which such probability-based quantities as half-lives and cross-sections can be reliably predicted and verified experimentally with QM. Whether objective chance and determinism are really incompatible or not may depend on what view of the nature of laws is adopted.

But what should a defender of a Humean view of laws, such as the BSA theory section 2. The first thing that needs to be done is explain how probabilistic laws can fit into the BSA account at all, and this requires modification or expansion of the view, since as first presented the only candidates for laws of nature are true universal generalizations.

We allow universal generalizations whose logical form is something like: See the entry on interpretations of probability and Lewis Humeans about laws believe that what laws there are is a matter of what patterns are there to be discerned in the overall mosaic of events that happen in the history of the world.

It seems plausible enough that the patterns to be discerned may include not only strict associations whenever X , Y , but also stable statistical associations. If the laws of nature can include either sort of association, a natural question to ask seems to be: If a Humean wanted to capture the laws not only of fundamental theories, but also non-fundamental branches of physics such as classical statistical mechanics, such a peaceful coexistence of deterministic laws plus further probabilistic laws would seem to be desirable.

In the introduction, we noted the threat that determinism seems to pose to human free agency. It is hard to see how, if the state of the world years ago fixes everything I do during my life, I can meaningfully say that I am a free agent, the author of my own actions, which I could have freely chosen to perform differently.

After all, I have neither the power to change the laws of nature, nor to change the past! So in what sense can I attribute freedom of choice to myself? Philosophers have not lacked ingenuity in devising answers to this question. There is a long tradition of compatibilists arguing that freedom is fully compatible with physical determinism; a prominent recent defender is John Fischer , There have been equally numerous and vigorous responses by those who are not convinced.

Can a clear understanding of what determinism is, and how it tends to succeed or fail in real physical theories, shed any light on the controversy? Physics, particularly 20 th century physics, does have one lesson to impart to the free will debate; a lesson about the relationship between time and determinism. Recall that we noticed that the fundamental theories we are familiar with, if they are deterministic at all, are time-symmetrically deterministic.

That is, earlier states of the world can be seen as fixing all later states; but equally, later states can be seen as fixing all earlier states. We tend to focus only on the former relationship, but we are not led to do so by the theories themselves.

Nor does 20 th 21 st -century physics countenance the idea that there is anything ontologically special about the past, as opposed to the present and the future.

In fact, it fails to use these categories in any respect, and teaches that in some senses they are probably illusory. But these pragmatic matters have nothing to do with fundamental determinism.

If we shake loose from the tendency to see the past as special, when it comes to the relationships of determination, it may prove possible to think of a deterministic world as one in which each part bears a determining—or partial-determining—relation to other parts, but in which no particular part region of space-time, event or set of events, Hoefer a and Ismael use such considerations to argue in a novel way for the compatiblity of determinism with human free agency.

Bohmian mechanics Russell, Bertrand space and time: The author would like to acknowledge the invaluable help of John Norton in the preparation of this entry. Thanks also to A. Ilhamy Amiry for bringing to my attention some errors in an earlier version of this entry. Conceptual Issues in Determinism 2. The Epistemology of Determinism 3. The Status of Determinism in Physical Theories 4. Chance and Determinism 6. Introduction In most of what follows, I will speak simply of determinism , rather than of causal determinism.

In order to get started we can begin with a loose and nearly all-encompassing definition as follows: The world is governed by or is under the sway of determinism if and only if, given a specified way things are at a time t , the way things go thereafter is fixed as a matter of natural law. As the following famous expression of determinism by Laplace shows, however, the two are also easy to commingle: We ought to regard the present state of the universe as the effect of its antecedent state and as the cause of the state that is to follow.

An intelligence knowing all the forces acting in nature at a given instant, as well as the momentary positions of all things in the universe, would be able to comprehend in one single formula the motions of the largest bodies as well as the lightest atoms in the world, provided that its intellect were sufficiently powerful to subject all data to analysis; to it nothing would be uncertain, the future as well as the past would be present to its eyes. The perfection that the human mind has been able to give to astronomy affords but a feeble outline of such an intelligence.

Laplace In this century, Karl Popper defined determinism in terms of predictability also, in his book The Open Universe.

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Some determinists argue that materialism does not present a complete understanding of the universe, because while it can describe determinate interactions among material things, it ignores the minds or souls of conscious beings.

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Determinism definition is - a theory or doctrine that acts of the will, occurrences in nature, or social or psychological phenomena are causally determined by preceding events or natural laws. How to use determinism in a sentence.

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Define determinists. determinists synonyms, determinists pronunciation, determinists translation, English dictionary definition of determinists. n. The philosophical doctrine that every state of affairs, including every human event, act, and decision, is the inevitable consequence of antecedent. Determinism is the philosophical idea that every event or state of affairs, including every human decision and action, is the inevitable and necessary consequence of antecedent states of affairs. More strictly, determinism should be distinguished from pre-determinism, the idea that the entire past (as well as the future) was determined at the origin of the universe.

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Determinism is the view that, given the state of the universe (the complete physical properties of all its parts) at a certain time and the laws of nature operative in the universe at that time, the state of the universe at any subsequent time. noun. Also called: necessitarianism the philosophical doctrine that all events including human actions and choices are fully determined by preceding events and states of affairs, and so that freedom of choice is illusory Compare free will (def. 1b) the scientific doctrine that all occurrences in nature take place in accordance with natural laws; the principle in classical mechanics that the.