The History of Chance
Chance is often defined as the opposite of Necessity. The English word derives from the Latin cadere - to fall, especially cadens a fall, falling. Dictionary definitions refer to the fall of the dice, but the etymology suggests it is related to the grammatical idea of declension, which describes the falling or "leaning" away of the genitive, dative, and accusative cases from the "straight up" nominative case. The word connotes falling in the sense of decadence. Note the German for chance is Zufall.
Leucippus (440 B.C.E.) stated the first dogma of determinism, an absolute necessity.
Nothing occurs by chance (maton), but there is a reason (logos) and necessity (ananke) for everything.Chance is regarded as inconsistent with causal determinism and with physical or mechanical determinism. The idea that Chance and Necessity are the only two logical options, and that neither is compatible with free will and moral responsibility, is the basis for the standard argument against free will. The first thinker to suggest a physical explanation for chance in the universe was Epicurus. Epicurus was influenced strongly by Aristotle, who regarded chance as a fifth cause. He said there must be cases in which the normally straight paths of atoms in the universe occasionally bend a little and the atoms "swerve" to prevent the universe and ourselves from being completely determined by the mechanical laws of Democritus. For Epicurus, the chance in his atomic swerve was simply a means to deny the fatalistic future implied by determinism (and necessity). As the Epicurean Roman Lucretius explained the idea,
...if all motion is always one long chain, and new motion arises out of the old in order invariable, and if the first-beginnings do not make by swerving a beginning of motion such as to break the decrees of fate, that cause may not follow cause from infinity, whence comes this freedom in living creatures all over the earthEpicurus did not say the swerve was directly involved in decisions so as to make them random. His critics, ancient and modern, have claimed mistakenly that Epicurus did assume "one swerve - one decision." Some recent philosophers call this the "traditional interpretation" of Epicurean free will. On the contrary, following Aristotle, Epicurus thought human agents have an autonomous ability to transcend the necessity and chance of some events. This special ability makes us morally responsible for our actions.
Despite abundant evidence, many philosophers deny that real chance exists. If a single event is determined by chance, then ...some things happen of necessity (ἀνάγκη), others by chance (τύχη), others through our own agency (παρ’ ἡμᾶς).indeterminism would be true, they say, and undermine the very possibility of certain knowledge. Some go to the extreme of saying that chance makes the state of the world totally independent of any earlier states, which is nonsense, but it shows how anxious they are about chance. The Stoic Chrysippus (200 B.C.E.) said that a single uncaused cause could destroy the universe (cosmos), a concern shared by some modern philosophers, for whom reason itself would fail.
Everything that happens is followed by something else which depends on it by causal necessity. Likewise, everything that happens is preceded by something with which it is causally connected. For nothing exists or has come into being in the cosmos without a cause. The universe will be disrupted and disintegrate into pieces and cease to be a unity functioning as a single system, if any uncaused movement is introduced into it.The core idea of chance and indeterminism is closely related to the idea of causality. Indeterminism for some is simply an event without a cause, an uncaused cause or causa sui that starts a new causal chain. If we admit some uncaused causes, we can have an adequate causality without the physical necessity of strict determinism - which implies complete predictability of events and only one possible future. 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 "soft" causality, which recognizes prior uncaused events as causes, is undetermined and the result of chance alone. Even mathematical theorists of games of chance found ways to argue that the chance they described was somehow necessary and chance outcomes were actually determined. The greatest of these, Pierre-Simon Laplace, preferred to call his theory the "calculus of probabilities." With its connotation of approbation, probability was a more respectable term than chance, with its associations of gambling and lawlessness. For Laplace, the random outcomes were not predictable only because we lack the detailed information to predict. As did the ancient Stoics, Laplace explained the appearance of chance as the result of human ignorance. He said,
"The word 'chance,' then expresses only our ignorance of the causes of the phenomena that we observe to occur and to succeed one another in no apparent order."Decades before Laplace, Abraham de Moivre had discovered the normal distribution (the bell curve) of outcomes for ideal random processes, like the throw of dice. Perfectly random processes produce a regular distribution pattern for many trials (the law of large numbers). Inexplicably, the discovery of these regularities in various social phenomena led Laplace and others to conclude that the phenomena were determined, not random. They simply denied chance in the world.
"It was the experimental physicist, Franz Exner, who for the first time, in 1919, launched a very acute philosophical criticism against the taken-for-granted manner in which the absolute determinism of molecular processes was accepted by everybody. He came to the conclusion that the assertion of determinism was certainly possible, yet by no means necessary, and when more closely examined not at all very probable. "Exner's assertion amounts to this: It is quite possible that Nature's laws are of thoroughly statistical character. The demand for an absolute law in the background of the statistical law — a demand which at the present day almost everybody considers imperative — goes beyond the reach of experience."[Ironically, just four years later, after developing his continuous and deterministic wave theory of quantum mechanics, Schrödinger would himself "go beyond the reach of experience" searching for deterministic laws underlying the discontinuous, discrete, statistical and probabilistic indeterminism of the Bohr-Heisenberg school, to avoid the implications of absolute chance in quantum mechanics. Planck and Einstein too were repulsed by randomness and chance. "God does not play dice," was Einstein's famous remark.] A major achievement of the Ages of Reason and Enlightenment was to banish absolute chance as unintelligible and atheistic. Newton's Laws provided a powerful example of deterministic laws governing the motions of everything. Surely Leucippus' and Democritus' original insights had been confirmed. In 1718 Abraham De Moivre wrote a book called The Doctrine of Chances. It was very popular among gamblers. In the second edition (1738) he derived the mathematical form of the normal distribution of probabilities, but he denied the reality of chance. Because it implied events that God could not know, he labeled it atheistic.
Chance, in atheistical writings or discourse, is a sound utterly insignificant: It imports no determination to any mode of existence; nor indeed to existence itself, more than to non existence; it can neither be defined nor understood.As early as 1784, Immanuel Kant had argued that the regularities in social events from year to year showed that they must be determined.
"Thus marriages, the consequent births and the deaths, since the free will seems to have such a great influence on them, do not seem to be subject to any law according to which one could calculate their number beforehand. Yet the annual (statistical) tables about them in the major countries show that they occur according to stable natural laws."In the early 1800's Adolphe Quetelet and Henry Thomas Buckle argued that these regularities in social physics proved that individual acts like marriage and suicide were determined by natural law. Franz Exner was not alone in defending chance before quantum uncertainty. In the nineteenth century in America, Charles Sanders Peirce coined the term "tychism" for his idea that absolute chance was the first step in three steps to "synechism" or continuity. Peirce was influenced by the social statisticians, Buckle and Quetelet, by French philosophers Charles Renouvier and Alfred Fouillee, who also argued for some absolute chance, by physicists James Clerk Maxwell and Ludwig Boltzmann, but most importantly by Kant and Hegel, who saw things arranged in the triads that Peirce so loved. Quetelet and Buckle thought they had established an absolute deterministic law behind all statistical laws. Buckle went so far as to claim it established the lack of free will. Renouvier and Fouillee introduced chance or indeterminism simply to contrast it with determinism, and to discover some way, usually a dialectical argument like that of Hegel, to reconcile the opposites. Renouvier argues for human freedom, but nowhere explains exactly how chance might contribute to that freedom, other than negating determinism. Maxwell may have used the normal distribution of Quetelet and Buckle's social physics as his model for the distribution of molecular velocities in a gas. Boltzmann also was impressed with the distribution of social statistics, and was initially convinced that individual particles obeyed strict and deterministic Newtonian laws of motion. Peirce does not explain much with his Tychism, and with his view that continuity and evolutionary love is supreme, may have had doubts about the importance of chance. Peirce did not propose chance as directly or indirectly providing free will. He never mentions the ancient criticisms that we cannot accept responsibility for chance decisions. He does not really care for chance as the origin of species, preferring a more deterministic and continuous lawful development, under the guidance of evolutionary love. But Peirce does say clearly, well before Exner, that the observational evidence simply does not establish determinism. It remained for William James, Peirce's close friend, to assert that chance can provide random unpredictable alternatives from which the will can choose or determine one alternative. James was the first thinker to enunciate clearly a two-stage decision process, with chance in a present time of random alternatives, leading to a choice which selects one alternative and transforms an equivocal ambiguous future into an unalterable determined past. There are undetermined alternatives followed by adequately determined choices.
"The stronghold of the determinist argument is the antipathy to the idea of chance...This notion of alternative possibility, this admission that any one of several things may come to pass is, after all, only a roundabout name for chance... What is meant by saying that my choice of which way to walk home after the lecture is ambiguous and matter of chance?...It means that both Divinity Avenue and Oxford Street are called but only one, and that one either one, shall be chosen." (James, The Dilemma of Determinism, in The Will to Believe, 1897, p.155)Chance is critically important for the question of free will because strict necessity implies just one possible future. Absolute chance means that the future is fundamentally unpredictable at the levels where chance is dominant. Chance allows alternative futures and the question becomes how the one actual present is realized from these potential alternative futures. The amount of chance and the departure from strict causality required for free will is very slight compared to the miraculous ideas often associated with the "causa sui" (self-caused cause) of the ancients. For medieval philosophers, only God could produce a causa sui, a miracle. Modern quantal randomness, unless amplified to the macroscopic world, is often insignificant, not a miracle at all. Despite David Hume's critical attack on causality, many philosophers embrace causality strongly, including Hume himself in his other writings, where he dogmatically asserts "'tis impossible to admit of any medium betwixt chance and an absolute necessity." Since Chrysippus twenty-two centuries ago, philosophers still connect causality to the very possibility of logic and reason. 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." (Russell, External World p.179) Although he felt some claims for causality might be excessive, Russell was unwilling to give up strict determinism, saying "Where determinism fails, science fails."(Determinism and Physics, p.18) Henri Poincaré said "Every phenomenon, however trifling it be, has a cause, and a mind infinitely powerful and infinitely well-informed concerning the laws of nature could have foreseen it from the beginning of the ages. If a being with such a mind existed, we could play no game of chance with him; we should always lose. For him, in fact, the word chance would have no meaning, or rather there would be no such thing as chance." We know that even in a world with microscopic chance, macroscopic objects are determined to an extraordinary degree. Newton's laws of motion are deterministic enough to send men to the moon and back. In our Cogito model, the Macro Mind is macroscopic 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 kind of determinism "adequate determinism." Despite quantum uncertainty, the world is adequately determined to send men to the moon. Quantum uncertainty leads some philosophers to fear an undetermined world of chance, one where Chrysippus' imagined collapse into chaos would occur and reason itself would fail us. But the modest indeterminism required for free will is no chaotic irrational threat, since most physical and mental events are overwhelmingly "adequately determined." There is no problem imagining that the three traditional mental faculties of reason - perception, conception, and comprehension - are all carried on with "adequate determinism" in a physical brain where quantum events and thermal noise do not interfere with normal operations. There is also no problem imagining a role for chance in the brain in the form of quantum level noise (as well as pre-quantal thermal noise). Noise can introduce random errors into stored memories. Noise could create random associations of ideas during memory recall. Many scientists have speculated that this randomness may be driven by microscopic fluctuations that are amplified to the macroscopic level. This would not happen in some specific location in the brain. It is most likely a general property of all neurons. We distinguish seven increasingly sophisticated ideas about the role of chance and indeterminism in the question of free will. Many libertarians have accepted the first two. Determinist and compatibilist critics of free will make the third their central attack on chance, claiming that it denies moral responsibility. But very few thinkers appear to have considered all seven essential requirements for chance to contribute to libertarian free will.