"Where determinism fails, science fails." (Determinism and Physics, 1936, vol.18).
In Part One, Chapter V, of his 1948 Human Knowledge: Its Scope and Limits
, Russell argues for a thorough-going mechanical determinism
of brain processes, but he does make a rare mention of quantum uncertainty
that may be based on Arthur Stanley Eddington
's ideas, which in any case was the basis for David Wiggins
' suggestion for an amplified quantum uncertainty. In his 1978 book Brainstorms
p.288, Daniel Dennett
quoted Wiggins and called this "Russell's Hunch."
It may be that, without infringing the laws of physics, intelligence could make improbable things happen, as Maxwell's demon would have defeated the second law of thermodynamics by opening the trap door to fast-moving particles and closing it to slow-moving ones...
It may be maintained that one characteristic of living matter is a condition of unstable equilibrium, and that this condition is most highly developed in the brains of human beings...Perhaps in the brain the unstable equilibrium is so delicate that the difference between two possible occurrences in one atom suffices to produce macroscopic differences in the movement of muscles...we may imagine that, in a brain, the choice between possible transitions is determined by a psychological cause called "volition."
Human Knowledge: Its Scope and Limits, 1948, Part One, Chapter V, pp.40-41
Although quantum mechanical, Russell's "hunch" proves to be little more than the clinamen
or the delicately balanced state of mind that James Clerk Maxwell
(or John Eccles
) was looking for, so that an infinitesimally small nudge by the mind
could tip the material body one way or the other, something like Robert Kane
's "self-forming actions." It is definitely not our two-stage model of free will
And although Russell knows the history of philosophy better than most professional philosophers, he appears blissfully unaware of the ancient and well-known criticism of chance as the direct cause of action
, which eliminates moral responsibility
(except, of courses, when the agent deliberately invokes indeterminism and is prepared to take responsibility for any outcome, as argued by Robert Kane
Russell also put forth a strong argument for denying the existence of God (Russell's Teapot") and a very weak argument claiming that any philosophical problem that is solved will be withdrawn from philosophy and added to science. We disagree with this argument, which we call "Russell's Residue."
In 1929, Frank Ramsey
made this suggestion in his book Theories. The Foundation of Mathematics
(p.235 in the 1960 edition),
Take, for instance, the problem "Is there a planet of the size and shape of a tea-pot?" This question has meaning so long as we do not know that an experiment could not decide the matter. Once we know this it loses meaning, unless we restore it by new axioms, e.g. an axiom as to the orbits possible to planets.
In a never-published article titled "Is There a God?" commissioned by Illustrated
magazine in 1952, Russell wrote:
Many orthodox people speak as though it were the business of sceptics to disprove received dogmas rather than of dogmatists to prove them. This is, of course, a mistake. If I were to suggest that between the Earth and Mars there is a china teapot revolving about the sun in an elliptical orbit, nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes. But if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense. If, however, the existence of such a teapot were affirmed in ancient books, taught as the sacred truth every Sunday, and instilled into the minds of children at school, hesitation to believe in its existence would become a mark of eccentricity and entitle the doubter to the attentions of the psychiatrist in an enlightened age or of the Inquisitor in an earlier time.
In 1958, Russell again suggested the teapot between Earth and Mars as a basis for his own atheism:
I ought to call myself an agnostic; but, for all practical purposes, I am an atheist. I do not think the existence of the Christian God any more probable than the existence of the Gods of Olympus or Valhalla. To take another illustration: nobody can prove that there is not between the Earth and Mars a china teapot revolving in an elliptical orbit, but nobody thinks this sufficiently likely to be taken into account in practice. I think the Christian God just as unlikely.
Principia Mathematica on Identity
, Volume 1, Second Edition, 1927, p.168
Part I, Mathematical Logic
Section B, Theory of Apparent Variables
The propositional function "x is identical with y" will be written "x = y."
We shall find that this use of the sign of equality covers all the common uses
of equality that occur in mathematics. The definition is as follows:
*1301. x = y . = : (φ) : φ ! x . ⊃ . φ ! y Df
Without mentioning Leibniz, this is the first use of Leibniz' Law of the Identity of Indiscernibles.
This definition states that x and y are to be called identical when every
predicative function satisfied by x is also satisfied by y. We cannot state that
every function satisfied by x is to be satisfied by y, because x satisfies functions
of various orders, and these cannot all be covered by one apparent variable.
But in virtue of the axiom of reducibility it follows that, if x = y and x satisfies
ψx, where ψ is any function, predicative or non-predicative, then y also satisfies
ψy (cf. *13.101., below). Hence in effect the definition is as powerful as it
would be if it could be extended to cover all functions of x...
The propositions of the present number are constantly referred to. Most
of them are self-evident, and the proofs offer no difficulty. The most important
of the propositions of this number are the following:
*13.101. ⊢ : x = y. ⊃ . ψx ⊃ ψy
I.e. if x and y are identical, any property of x is a property of y.
*13.12. ⊢ : x = y . ⊃ ψx ≡ ψy
This includes *13.101 together with the fact that if x and y are identical
any property of y is a property of x.
*22.214.171.124. which state that identity is reflexive, symmetrical and transitive.
In an early work, Russell asserted that today “utility does not belong to philosophy.” Philosophical problems with solutions become science, he said.
"If all men were well off, if poverty and disease had been reduced to their lowest possible point, there would still remain much to be done to produce a valuable society; and even in the existing world the goods of the mind are at least as important as the goods of the body."
"But it cannot be maintained that philosophy has had any very great measure of success in its attempts to provide definite answers to its questions… as soon as definite knowledge concerning any subject becomes possible, this subject ceases to be called philosophy, and becomes a separate science. The whole study of the heavens, which now belongs to astronomy, was once included in philosophy; Newton's great work was called 'the mathematical principles of natural philosophy'. Similarly, the study of the human mind, which was a part of philosophy, has now been separated from philosophy and has become the science of psychology.
“to a great extent, the uncertainty of philosophy is more apparent than real..." [When philosophical questions are resolved they leave the philosophical realm.] “while those only to which, at present, no definite answer can be given, remain to form the residue which is called philosophy."
There are many questions -- and among them those that are of the profoundest interest to our spiritual life -- which, so far as we can see, must remain insoluble to the human intellect unless its powers become of quite a different order from what they are now. Has the universe any unity of plan or purpose, or is it a fortuitous concourse of atoms? Is consciousness a permanent part of the universe, giving hope of indefinite growth in wisdom, or is it a transitory accident on a small planet on which life must ultimately become impossible?"
(The Problems of Philosophy, 1912, pp.89-90)
"[t]he value of philosophy is, in fact, to be sought largely in its very uncertainty"
"The man who has no tincture of philosophy goes through life imprisoned in the prejudices derived from common sense, from the habitual beliefs of his age or his nation, and from convictions which have grown up in his mind without the co-operation or consent of his deliberate reason. To such a man the world tends to become definite, finite, obvious; common objects rouse no questions, and unfamiliar possibilities are contemptuously rejected.
Russell was overstating the case when he said "what science cannot discover, mankind cannot know," and later in The Problems of Philosophy
"questions which are already capable of definite answers are placed in the sciences, while those only to which, at present, no definite answer can be given, remain to form the residue which is called philosophy."
(The Problems of Philosophy, 1912, p.155)
can not be reduced to "Russell's Residue."
The goal of information philosophy
is not to remove a problem from philosophy once it is solved. To be sure, where scientists seek solutions, philosophers prefer problems, ones that are teachable as problems
. But these attitudes only serve to prevent progress in philosophy.
The Physiology of Sensation and Volition
From the standpoint of orthodox psychology, there are two boundaries between the mental and physical, namely, sensation and volition. "Sensation" may be defined as the first mental effect of a physical cause, "volition" as the last mental cause of a physical effect. I am not maintaining that these definitions will prove ultimately satisfactory, but only that they may be adopted as a guide in our preliminary survey. In the present chapter I shall not be concerned with either sensation or volition themselves, since they belong to psychology; I shall be concerned only with the physiological antecedents and concomitants of sensation, and with the physiological concomitants and consequents of volition. Before considering what science has to say, it will be worth while to view the matter first from a common-sense point of view.
Suppose something is said to you, and in consequence you take some action; for example, you may be a soldier obeying the word of command. Physics studies the sound waves that travel through the air until they reach the ear; physiology studies the consequent events in the ear and nerves and brain, up to the moment when you hear the sound; psychology studies the sensation of hearing and the consequent volition; physiology then resumes the study of the process, and considers the outgoing chain of events from the brain to the muscles and the bodily movement expressing the volition; from that point onward, what happens is again part of the subject matter of physics. The problem of the relation of mind and matter, which is part of the stock in trade of philosophy, comes to a head in the transition from events in the brain to the sensation, and from the volition to other events in the brain. It is thus a twofold problem: how does matter affect mind in sensation, and how does mind affect matter in volition? I do not propose to consider this problem at this stage; I mention it now only to show the relevance of certain parts of physiology to questions which philosophy must discuss.
The physiological processes which precede and accompany sensation are admirably set forth in Adrian's book The Basis of Sensation: The Action of the Sense Organs (London, 1928). As everyone knows, there are two sorts of nerve fibers, those that carry messages into the brain and those that carry messages out of it. The former alone are concerned in the physiology of sensation. Isolated nerves can be stimulated artificially by an electric current, and there is good reason to believe that the processes thus set up are essentially similar to those setup naturally in nerves that are still in place in a living body. When an isolated nerve is thus stimulated in an adequate manner, a disturbance is set up which travels along the nerve at a speed of about 220 miles an hour (100 meters a second). Each nerve consists of a bundle of nerve fibers running from the surface of the body to the brain or the spinal cord. The nerve fibers which carry messages to the brain are called "afferent"; those which carry messages from the brain are called "efferent." A nerve usually contains both afferent and efferent fibers. Broadly speaking, the afferent fibers start from sense organs and the efferent fibers end in muscles.
The response of a nerve fiber to a stimulus is of what is called the "all-or-nothing" type, like the response of a gun to pressure on the trigger. A slight pressure on the trigger produces no result, but a pressure which is sufficiently great produces a specific result which is the same however great the pressure may be (within limits). Similarly when a nerve fiber is stimulated very slightly, or for a very brief period (less than .00001 of a second), there is no result, but when the stimulus is sufficient a current travels along the nerve fiber for a very brief period (a few thousandths of a second), after which the nerve fiber is "tired" and will not transmit another current until it is rested. At first, for two or three thousandths of a second, the nerve fiber is completely refractory; then it recovers gradually. During the period of recovery a given stimulus produces a smaller response, and one which travels more slowly. Recovery is complete after about a tenth of a second. The result is that a constant stimulus does not produce a constant state of excitement in the nerve fibers, but a series of responses with quiescent periods between. The messages that reach the brain are, as Adrian puts it, like a stream of bullets from a machine gun, not like a continuous stream of water.
It is supposed that in the brain, or the spinal column, there is a converse mechanism which reconverts the discrete impulses into a continuous process, but this, so far, is purely hypothetical.
Owing to the discontinuous nature of the response to a stimulus, the response will be exactly the same to a constant stimulus as to one which is intermittent with a frequency adapted to the period of recovery in the nerve. It would seem to follow that there can be no means of knowing whether the stimulus is constant or intermittent. But this is not altogether true. Suppose, for instance, that you are looking at a bright spot of light: if you could keep your eyes absolutely fixed, your sensations would be the same if the light flickered with appropriate rapidity as they would be if the light were steady. But in fact it is impossible to keep the eyes quite still, and therefore fresh, unfatigued nerves are perpetually being brought into play.
A remarkable fact, which might seem to put a limit on the informative value of sensations, is that the response of the nerve fiber is the same to any stimulus of sufficient strength and duration: there is just one message, and only one, that a given nerve fiber can transmit. But consider the analogy of a typewriter: if you press a given letter, only one result occurs, and yet the typewriter as a whole can transmit any information, however complicated.
The mechanism of the efferent nerve fibers appears to be just the same as that of the afferent nerve fibers; the messages that travel from the brain to the muscles have the same jerky character as those that travel from the sense organs to the brain.
But the most interesting question remains. What goes on in the brain between the arrival of a message by the afferent nerves and the departure of a message by the efferent nerves? Suppose you read a telegram saying, "All your property has been destroyed in an earthquake," and you exclaim, "Heavens! I am ruined!" We feel, rightly or wrongly, that we know the psychological links, after a fashion, by introspection, but everybody is agreed that there must also be physiological links. The current brought into the vision center by the optic nerve must pass thence to the speech center, and then stimulate the muscles which produce your exclamation. How this happens is still obscure. But it seems clear that from a physiological point of view there is a unitary process from the physical stimulus to the muscular response. In man this process may be rendered exceedingly complex by the operation of acquired habits, especially language habits, but in some less highly organized animals the process is simpler and less difficult to study; the reason why the moth approaches the flame, for example, is fairly well understood in physiological terms.
Is Russell proposing a demon here predicting the actions of a brain?
This raises a question of great interest, namely: Is the process in the brain, which connects the arrival of the sensory stimulus with the departure of the message to the muscles, completely explicable in physical terms? Or is it necessary to bring in "mental" intermediaries, such as sensation, deliberation, and volition? Could a superhuman calculator, with sufficient knowledge of the structure of a given brain, predict the muscular response to a given stimulus by means of the laws of physics and chemistry? Or is the intervention of mind an essential link in connecting a physical antecedent (the stimulus) with a physical consequent (a bodily movement)?
Until more is known about the brain than is known at present, it will not be possible to answer this question confidently in either sense. But there are already some grounds, though not conclusive ones, for regarding what might be called the materialist answer as the more probable one. There are reflexes, where the response is automatic and not controlled by volition. From unconditioned reflexes, by the law of habit, conditioned reflexes arise, and there is every reason to regard habit as physiologically explicable. Conditioned reflexes suffice to explain a great part of human behavior; whether there is a residue that cannot be so explained must remain, for the present, an open question.
At a later stage, I shall maintain that there is no such gulf between the mental and the physical as common sense supposes. I shall also maintain that even if the physiological causal chain from sense organ to muscle can be set forth in terms which ignore the psychological occurrences in the middle of the chain, that will not prove that volitions are not "causes" in the only valid sense of the word "cause." But both of these contentions require considerable argument and elucidation. For the present, I will only add a few words from the standpoint of scientific common sense.
If — as seems likely — there is an uninterrupted chain of purely physical causation throughout the process from sense organ to muscle, it follows that human actions are determined in the degree to which physics is deterministic. Now physics is only deterministic as regards macroscopic occurrences, and even in regard to them it asserts only very high probability, not certainty. It might be that, without infringing the laws of physics, intelligence could make improbable things happen, as Maxwell's demon would have defeated the second law of thermodynamics by opening the trap door to fast-moving particles and closing it to slow-moving ones.
On these grounds it must be admitted that there is a bare possibility — no more — that although occurrences in the brain do not infringe the laws of physics, nevertheless their outcome is not what it would be if no psychological factors were involved. I say there is no more than
a bare possibility for several reasons. In the first place, the hypothesis supposes only the microscopic laws preserved, not the macroscopic laws. But the evidence for the macroscopic laws is better than the evidence for the microscopic laws, and very strong grounds would be needed to justify a belief that on some occasion they had failed. In the second place, all the occurrences which illustrate the connection of mind and matter are macroscopic: a volition, for example, results in a perceptible bodily movement, not in a mere atomic change. In the third place, the study of processes in the nerves and brain, so far, has shown physical causation wherever adequate observation was possible; the region as to which there is still ignorance is one where very minute phenomena are concerned, and where observation is very difficult. There is therefore, so far, not the smallest positive reason for supposing that there is anything about physical processes in the brain that involves different macroscopic laws from those of the physics of inanimate matter.
Nevertheless, for those who are anxious to assert the power of mind over matter it is possible to find a loophole. It may be maintained that one characteristic of living matter is a condition of unstable equilibrium, and that this condition is most highly developed in the brains of human beings. A rock weighing many tons might be so delicately poised on the summit of a conical mountain that a child could, by a gentle push, send it thundering down into any of the valleys below; here a tiny difference in the initial impulse makes an enormous difference to the result.
Perhaps in the brain the unstable equilibrium is so delicate that the difference between two possible occurrences in one atom suffices to produce macroscopic differences in the movements of muscles. And since, according to quantum physics, there are no physical laws to determine which of several possible transitions a given atom will undergo, we may imagine that, in a brain, the choice between possible transitions is determined by a psychological cause called "volition." All this is possible, but no more than possible; there is not the faintest positive reason for supposing that anything of the sort actually takes place.
On the evidence as it exists the most probable hypothesis is that, in the chain of events from sense organ to muscle, everything is determined by the laws of macroscopic physics. To return to our previous illustration of the man who reads a telegram and exclaims, "I am ruined!": it seems probable that if you had a sufficiently minute knowledge of his brain structure, and if you were a sufficiently good mathematician, you could foretell that when the shapes making the message on the telegram came into his field of vision they would set up a process ending in certain movements in his mouth, to wit, those producing the sounds which we represent in writing as "I am ruined."
Here is a random microscopic event amplified to determine volition. Compare Maxwell's unstable equilibrium
. But note the idea that psychological processes can influence quantum transitions.
It is here assumed that you could make this prophecy without knowing English; it should not be necessary for you to know the meaning either of the telegram or of his exclamation. The difference between a man knowing English and a man not knowing it should, on the physiological side, consist in the presence in one case, and absence in the other, of connections between the afferent nerves when stimulated by the hearing or reading of English words and the efferent nerves producing the appropriate response. This difference we suppose visible to a hypothetical observer without his having to know the "meaning" either of the stimulus or of the response.
This hypothesis, it must be admitted, does not seem very plausible, and I am far from asserting dogmatically that it is true. The most that can legitimately be asserted, in my opinion, is that it is the right working hypothesis for a man investigating the physiological concomitants of sensation and volition. In so far as it is true, it may help him to make discoveries; if, at some point, it is false, its falsehood is most likely to be discovered by means of experiments suggested by the assumption of its truth. In so far as the hypothesis is true, physiology is a science independent of psychology; if at any point it is false, physiology ceases to be autonomous. Asa matter of practical policy, the physiologist does well to assume that his science is autonomous so long as no evidence to the contrary has been discovered.
Russell's demon is like the man in John Searle
's Chinese Room.
("The Physiology of Sensation and Volition," Part One, Chapter V, Human Knowledge: Its Scope and Limits, 1948, pp.36-42)
The History of Materialism
In 1925, Russell wrote an introduction to the English translation of the second edition of Frederick Albert Lange's monograph The History of Materialism
In it, Russell presents the case for and against materialism (and determinism) substantially as that case is presented today. (Compare for example, Galen Strawson
's Real Materialism
. So much for progress in philosophy!)
Below we present an annotated version of Russell's short review, with a few annotations describing present views. (A PDF version of the original is here
MATERIALISM, PAST AND PRESENT
MATERIALISM as a theory of the nature of the world has had
a curious history. Arising almost at the beginning of Greek
philosophy, it has persisted down to our own time, in spite
of the fact that very few eminent philosophers have
advocated it. It has been associated with many scientific
advances, and has seemed, in certain epochs, almost
synonymous with a scientific outlook. Accusations of
materialism have always been brought by the orthodox
against their opponents, with the result that the less
discriminating opponents have adopted materialism because
they believed it to be an essential part of their opposition.
At the present moment, the official creed of one of the
largest States in the world is materialism, although hardly
any one in the learned world explicitly adheres to this
theory. A system of thought which has such persistent
vitality must be worth studying, in spite of the professional
contempt which is poured on it by most professors of
Lange's History of Materialism, here re-issued in "The
International Library of Psychology, Philosophy, and
Scientific Method," is a monumental work, of the highest
value to all who wish to know what has been said by
advocates of materialism, and why philosophers have in
the main remained unconvinced. The first edition appeared
in 1865, at the height of the period often described as
"The materialistic '60's." The preface to the second
edition is dated June, 1873. The author died in 1875,
before the reaction against materialism had made itself
felt. Lange, while very sympathetic to materialism in its
struggles with older dogmatic systems, was himself by no
means a materialist. He is described by Professor Cohen,
in the Preface to the Ninth Edition (1921), as an "apostle
of the Kantian view of the world," to which Professor
Cohen himself adheres. The description is quite correct.
Lange considers that materialism is unable to explain
consciousness, and is refuted, on scientific grounds, by the
psychology and physiology of sensation, which shows that
the world studied by physics is a world dependent on our
modes of perception, not a world existing independently on
its own account.
It is a commonplace to object to materialism on ethical
grounds, since it is supposed to have a deleterious effect on
conduct. While energetically repelling many forms of this
criticism, Lange nevertheless upholds it in the end, since
he regards the economics of the Manchester school and the
ruthlessness of modern competition as attributable to a
materialistic outlook. This is perhaps the weakest part of
his book, in spite of the fact that, unlike most German
learned men, he had considerable experience of practical
life. In 1861, at the age of 33, he resigned his position as a
teacher, and became secretary of the Duisburg Chamber of
Commerce. But his position became difficult owing to his
radical opinions, which found vent in various directions.
He edited a newspaper called The Rhine and Ruhr Gazette,
and he wrote a book called Die Arbeiterfrage in ihrer Bedeutung
fur Gegenwart und Zukunft, which appeared in the
same year as his History of Materialism. His industry was
little short of miraculous, for in this same year he published
yet another book, Die Grundlegung der mathematischen
Psychologie — and all this without neglecting the newspaper
or the Chamber of Commerce.
In the following year (1866) he went to Switzerland,
where he again took up academic work, becoming Professor
at Zurich in 1870, and returning to Germany in 1872 aB
Professor at Marburg. But his experiences in the world of
industry and commerce undoubtedly helped to widen his
outlook, and to give him an understanding, not always
possessed by the learned, of the operation of theories when
they pass out into the market-place. He remarks that, in
England, philosophers are often statesmen, and, what is
still more extraordinary, statesmen are sometimes philosophers.
He does not point out how often the mixture
is damaging to both, making the statesman too theoretical
and the philosopher too practical.
Lange's book is divided into two parts, one dealing with
the times before Kant, the other with Kant and his successors.
This division shows the very great importance
which he attaches to the philosopher of Konigsberg — an
importance which, perhaps, may seem less as time goes on.
Kant's system is intimately bound up with the state of the
exact sciences in his day: Euclidean geometry gives the
foundation of the transcendental aesthetic, and the Aristotelian
syllogism gives the ground for the deduction of the
categories. Now that geometry has become non-Euclidean
and logic non-Aristotelian, Kant's arguments require restatement; to what extent this is possible, is still a moot
question. To the present writer, the first half of Lange's
book appears considerably better than the second, because
it is less affected by the author's views on matters which
are still undecided. In the periods before Kant, his critical
judgment is extraordinarily sound. The account of Greek
atomism, the analysis of Plato's influence for good and
evil, are admirable. The combination of scientific materialism
with theological orthodoxy in seventeenth-century
England, and its contrast with the revolutionary materialism
of eighteenth-century France, are set forth with a nice
historical sense. But it is always a very difficult task to
see one's own time in historical perspective. Apart from
philosophical predilections, there is difficulty in disentangling
what is important and permanent in the purely scientific
work of one's own generation. The problems which occupied
the men of science sixty years ago were very different from
those of the present day, and it was impossible to know
which of them would prove to be historically important.
On the question: what is true and what false in materialism? it is possible to speak with more learning and more
complication than in former days, but it may be doubted
whether any substantially new arguments have been
invented since Greek times. Nevertheless, it may be
profitable to attempt a survey of the position as it appears
in the light of modern science.
The theory of Democritus was intelligible and simple.
The world consisted of hard round atoms of various sizes,
all falling, but the heavier atoms falling faster, so that they
would occasionally impinge upon the fighter atoms. If
the impact was not exactly in the line of centres, there
would be a resultant sideways motion, which accounts for
the fact that bodies do not move only in one direction.
This view, of course, had to be modified for purely physical
reasons, but the modifications were not important until
we come to Descartes with his plenum and his doctrine of
vortices. This showed that atomism is not an essential
part of materialistic physics. Newton's followers introduced another modification; namely, action at a distance
(which Newton himself still regarded as impossible). To
this day the oscillation continues between atoms with
action at a distance and a continuous medium (the aether)
with continuous transmission of effects. Few physicists
nowadays cling to either as a matter of principle; the
only question is: which best explains observed phenomena?
Both views have in common a belief in physical determinism,
i.e. a belief that what happens in the world dealt
with by physics happens according to laws such that, if
we knew the whole state of the physical world during a
finite time, however short, we could theoretically infer its
state at any earlier or later time. This is the kernel of
materialism from the standpoint of ethics, religion, sociology,
etc., though not from the standpoint of metaphysics. If
physical determinism is true — if, that is to say, everything
that we commonly regard as the motion of matter is subject
to laws of the above kind — then, although there may be a
concurrent world of mind, all its manifestations in human
and animal behaviour will be such as an ideally skilful
physicist could calculate from purely physical data. Physics
may still be unable to tell us anything about a man's
thoughts, but it will be able to predict all that he will say
and do. Under these circumstances, a man will be, for all
practical purposes, an automaton, since his mental life can
only be communicated to others or displayed in action by
physical means. Even his thoughts can be inferred from
physics, unless he is content never to give utterance to them.
This point of view resulted from Cartesianism, though
most Cartesians attempted to escape from its consequences.
Lamettrie, author of L'homme machine, justly claimed that
he had derived his philosophy from Descartes. Descartes,
who knew about the conservation of vis viva, but not
about the conservation of momentum, endeavoured to
safeguard human freedom by maintaining that the will
could alter the direction of motion of the animal spirits,
though not the amount of their motion. He did not,
however, extend this freedom to animals, which he regarded
as automata. Nowadays no one would dream of drawing
such a distinction between men and animals. And even
his immediate followers had to abandon his position on
this point, owing to the discovery of the conservation of
momentum, which showed that the quantity of motion
in each direction must be constant. From that day to our
own, many philosophers have advocated the theory of
two parallel series, one mental and one physical, each subject
to its own laws, and neither influencing the other. This
theory has less plausibility in our time than it had formerly;
but apart from the question of its truth, it is worth while
to realise that it does not afford an escape from the more
disagreeable consequences of materialism.
If there is parallelism between the physical and mental
series, as this theory supposes, every physical law must
have its psychological counterpart, and therefore psychology
must be as rigidly deterministic as physics. There will be,
so to speak, a dictionary, by which physical events can be
translated into the concurrent mental events. Given
this dictionary, the Laplacean calculator can, by physics
alone, deduce the state of the material world at any given
time, and discover from the dictionary what must be the
corresponding state of the mental world. Clearly, the
emancipation from physics which anti-materialists desire,
is not to be achieved along these lines.
There is, however, no good reason to accept the theory of
psycho-physical parallelism. The dualism of mind and
matter is probably not ultimate, and the supposed impossibility of interaction rests upon nothing better than scholastic
dogmas. To common-sense it appears that our minds
are affected by what we see and hear, and that, conversely,
our bodies are affected by our volitions whenever we will
to make any movement. There is no reason whatever to
suppose that common-sense is mistaken in this view,
although, of course, there is great need of analysis as to
what really takes place when we perceive or will.
Lange advances, quite justly, as an argument against
materialism, the fact that we only know about matter
through its appearances to us, which, according to materialism
itself, are profoundly affected by our own physical
organisation. What we see depends not only upon what
is there to be seen, but also upon the eye, the optic nerve,
and the brain. But the eye, the optic nerve, and the brain
are only known through being seen by the physiologist.
In this way materialism is driven back to sensationalism.
If it is to escape sensationalism, it must abandon the
empirical scientific method, substituting for it the dogmatism
of an a priori metaphysic, which professes to know
what is behind appearances. Historically, we may regard
materialism as a system of dogma set up to combat orthodox
dogma. As a rule, the materialistic dogma has not been
set up by men who loved dogma, but by men who felt that
nothing less definite would enable them to fight the dogmas
they disliked. They were in the position of men who raise
armies to enforce peace. Accordingly we find that, as
ancient orthodoxies disintegrate, materialism more and
more gives way to scepticism. At the present day, the
chief protagonists of materialism are certain men of science
in America and certain politicians in Russia, because it
is in those two countries that traditional theology is still
The two dogmas that constitute the essence of materialism
are: First, the sole reality of matter; secondly, the
"reign of law." The belief that matter alone is real will not
survive the sceptical arguments derived from the physiological
mechanism of sensation. But it has received recently
another blow, from the quarter whence it was least to be
expected, namely, from physics. The theory of relativity,
by merging time into space-time, has damaged the traditional
notion of substance more than all the arguments of
philosophers. Matter, for common-sense, is something
which persists in time and moves in space. But for modern
relativity-physics this view is no longer tenable. A piece
of matter has become, not a persistent thing with varying
states, but a system of inter-related events. The old
solidity is gone, and with it the characteristics that, to the
materialist, made matter seem more real than fleeting
thoughts. Nothing is permanent, nothing endures; the
prejudice that the real is the persistent must be abandoned.
The notion of substance has not been regarded by
philosophers as metaphysically valid since the time of
Hume and Kant, but it persisted in the practice of physics.
Its defeat, within physics, by the abandonment of a single
cosmic time affords a purely scientific argument against the
older type of materialism, which utilised the belief that
substance is what persists through time.
The reign of law raises more difficult and also more
important questions. The outlook with which the phrase
"reign of law" seems to belong most naturally is that of
Newton, especially as developed by his disciples. Belief
in the reign of law is often combined with strict theological
orthodoxy, but in that case human volitions are excepted, at
any rate in certain cases. The reign of law only becomes
part of the materialistic outlook when it is believed to
have no exceptions, not even human volitions. It is in this
form that we have to consider it. It will he necessary first
to define the phrase, and then to inquire what ground there
is for believing it applicable to the world.
The definition of the reign of law is by no means so easy
as seems often to be supposed. The idea is derived from
such instances as the law of gravitation in the solar system,
where a simple formula enables us to predict the motions
of the planets and their satellites. But this instance is
deceptive in several respects. In the first place, there is no
reason to suppose that the laws in other cases are equally
simple. In the second place, it turns out that the Newtonian
form of the law of gravitation is only approximate, and
that the exact law is enormously more complicated. In
the third place, the geography (if one may use such a term)
of the solar system is amazingly schematic. To a first
approximation, it may be regarded as consisting of a small
number of mass-points, whose individual motions are
easily observable. This point of view is not adequate for
dealing with such matters as tides, but it suffices for the
deduction of Kepler's laws from the law of gravitation,
which was Newton's most spectacular achievement. It is
obviously a very different matter to obtain laws applicable
to individual electrons and protons, because of the greater
geographical complexity involved. For these reasons,
among others, it is rash to regard the Newtonian astronomy
as typical of what is to be expected in physics.
The least that can be meant by the reign of law is this:
given any phenomenon, there exists some formula of finite
complexity such that, from a sufficient (finite) number of
data at other times the phenomenon in question can be
calculated. In practice, the "other times" will usually be
earlier times, but this is not always the case — for example,
in speculations as to the geological history of the earth or
the origin of the solar system. Theoretically, it should be
irrelevant whether the "other times" are earlier or later
than that of the phenomenon concerned.
In elucidation of the above definition, there are one or
two observations to be made. The reason for saying that
the formula must be of finite complexity is that otherwise
nothing is asserted beyond a logical truism. By admitting
formulae of infinite complexity, any series of events whatever
could be brought within the compass of a single law,
and therefore we should assert nothing in asserting the
reign of law. The reason for insisting that the number of
data required must be finite is similar, but is reinforced
by another, namely, that we cannot manipulate an indefinite number of data, and could therefore never discover
evidence either for or against a law which required them.
There is a further point which should be borne in mind.
None of our observations are completely accurate; there
is always a margin of error. Consequently we can never
prove that events obey exactly any law which is found to
work within the margin of error, nor, conversely, need we
trouble ourselves about inaccuracies which must remain
below this margin. For example: it is always assumed in
physics that continuous functions can be differentiated,
although, as a matter of pure mathematics, this is known
to be only sometimes the case. There is no harm in this
from the physicist's standpoint, because, given any continuous
function which cannot be differentiated, there will
always be another which can be differentiated, and which
differs from the first by less than the probable error in our
observations. Approximations are all that we can achieve,
and therefore all that we need attempt.
The question now arises: Is there any reason to believe
in the reign of law in the above sense? In the world of pure
physics there are a number of fundamental occurrences
which cannot at present be reduced to law. No one knows
why some atoms of a radio-active element disintegrate
while others do not; we know statistical averages, but
what goes on in the individual atom is completely obscure.
Again, the spectrum of an element is caused by electrons
jumping from one possible orbit to another. We know a
great deal about the possible orbits, and about what happens
when a jump takes place, and about the proportion that
choose one possible jump as compared to those that choose
another. But we do not know what (if anything) decides
the particular moment at which an electron jumps, or the
particular jump that it sees fit to make when several are
possible. Here, again, it is statistical averages that we
know. It is therefore open to anybody to say that, while
averages are subject to law, the actions of individual
electrons have a certain range of caprice, within which
there is no evidence for the reign of law. A man who
maintained such a view dogmatically would be very rash,
since to-morrow he might be refuted by some new discovery.
But a man who merely maintains that, in the present state
of physics, it is a possibility to be borne in mind, is displaying
a proper scientific caution. Thus even within the
pure physics of inorganic matter the reign of law cannot
he asserted to be indubitably universal.
This doubt cannot but be increased when we pass on to
biology and psychology. I do not mean that there is any
positive evidence against the reign of law in this region;
I mean only that the evidence in its favour is less strong,
because fewer laws are known, and prediction is as yet
only possible within very narrow limits. The discovery
of quanta in physics shows how rash it is to dogmatise
as to the further surprises which even an advanced science
may have in store for us; and psychology is by no means
an advanced science.
In the present condition of human knowledge, therefore,
either to assert or to deny the universal reign of law is a
mark of prejudice; the rational man will regard the question
as open. All perennial controversies, such as that between
determinists and believers in free will, spring from a conflict
between opposing passions, both widespread, but one
stronger in one man and the other in another. In this
case, the conflict is between the passion for power and the
passion for safety, because if the external world behaves
according to law we can adapt ourselves to it. We desire
the reign of law for the sake of safety, and freedom for the
sake of power. Common-sense assumes that law governs
inanimate nature and one's neighbours, while freedom is
reserved for oneself. In this way both passions are gratified
to the full. But philosophy demands some more subtle
reconciliation, and is therefore never weary of inventing
new ways of combining freedom with determination.
The sceptic can merely observe this struggle with detachment,
and he is fortunate if his detachment does not
degenerate into cynicism.
It has always been customary, and since the time of
Kant it has been thought even respectable, to invoke moral
considerations in support of freedom. While, however, the
sceptic has a good case as against the dogmatic believer in
the universal reign of law, he is not likely to admit the
opposite claim that a dogmatic disbelief in this principle
is helpful to morals. If he is a sceptic worthy of the name,
he will begin by saying that no one knows what beliefs
are helpful to morals, or even whether beliefs have any
noticeable influence on conduct. But if he is a student of
history, he will observe that, as a practical postulate,
belief in natural law has borne good fruit by producing
such knowledge as we possess, whereas its rejection has
been associated with intolerance and obscurantism. He
will say that, though possibly there may be phenomena
not reducible to law, this is a mere speculative possibility,
of which it is unnecessary to take account in the actual
practice of science, since science can only advance by the
discovery of laws, and where (if anywhere) there are no
laws, there is also no possible science.
In our own time, the old battle of materialism persists
chiefly in biology and physiology. Some men of science
maintain that the phenomena of living organisms cannot be
explained solely in terms of chemistry and physics; others
maintain that such explanation is always theoretically
possible. Professor J. S. Haldane may be regarded, in this
country, as the leading exponent of the former view; in
Germany it is associated with Driesch. One of the most
effective champions of the mechanistic view was Jacques
Loeb, who showed (inter alia) that a sea-urchin could have
a pin for its father, and afterwards extended this result to
animals much higher in the scale. The controversy may
be expected to last for a long time, since, even if the
mechanists are in the right, they are not likely soon to find
explanations of all vital phenomena of the sort that their
theory postulates. It will be a severe blow to the vitalists
when protoplasm is manufactured in the laboratory, but
they will probably take refuge in saying that their theories
only apply to multi-cellular organisms. Later, they will
confine vitalism to vertebrates, then to mammals, then to
men, and last of all to white men—or perhaps it will be i
yellow men by that time. Ordinary scientific probability
suggests, however, that the sphere of mechanistic explanation in regard to vital phenomena is likely to be indefinitely
extended by the progress of biological knowledge.
Psychology, which might have been expected to be more
opposed to materialism than any other science, has, on the
contrary, shown decided leanings in that direction. The
behaviourist school maintains that psychology should only
concern itself with what can be seen by external observation,
and denies totally that introspection is an independent
source of scientific knowledge. This view would make all
the phenomena with which psychology is concerned physical
phenomena, thereby conceding to materialism the utmost
of its claims. Apart, however, from other difficulties, there
is the difficulty already noted, that the data of physics are
sensations, which are infected with the subjectivity of the
observer. Physics seeks to discover material occurrences
not dependent upon the physiological and psychical
peculiarities of the observer. But its facts are only discovered
by means of observers, and therefore only afford
data for physics in so far as means exist of eliminating the
observer's contribution to the phenomenon. This elimination
is not an easy matter. It might be argued, on philosophical
grounds, that it is impossible, and this is no doubt
true if complete elimination is meant. But to a certain
extent the problem can be treated scientifically, without
raising metaphysical issues. It is then found that subjectivity
is of three kinds, physical, physiological, and psychical.
The first of these is satisfactorily dealt with by the theory
of relativity: the method of tensors is its complete theoretical
solution. The second and third are perhaps not
really distinct; they can be dealt with in so far as one
man's perceptions differ from another's, but it is difficult
to see any method of eliminating subjective elements in
which all men are alike.
There is one other respect in which psychology has been
tending towards the point of view advocated by materialists.
We used to hear much of such supposed faculties as
"consciousness," "thought," and "reason." Many modern
psychologists, following William James, are inclined to
dismiss "consciousness" as a term destitute of any clear
meaning. "Thought" and "reason," meanwhile, are
found to be analogous to processes of learning among
animals, which are ultimately reducible to the law of habit.
All this, of course, is still controversial; but if it should
prove correct, the psychological difficulties of materialism
will be greatly diminished.
The conclusion of the above discussion would seem to be
that, as a practical maxim of scientific method, materialism
may be accepted if it means that the goal of every science
is to be merged in physics. But it must be added that
physics itself is not materialistic in the old sense, since it no
longer assumes matter as permanent substance. And it
must also be remembered that there is no good reason to
suppose materialism metaphysically true: it is a point of
view which has hitherto proved useful in research, and is
likely to continue useful wherever new scientific laws are
being discovered, but which may well not cover the whole
field, and cannot, be regarded as definitely true without a
wholly unwarranted dogmatism.
Russell, B. (1905). On denoting
. Mind, 14(56), 479-493.
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