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Core Concepts

Adequate Determinism
Agent-Causality
Alternative Possibilities
Causa Sui
Causal Closure
Causality
Certainty
Chance
Chance Not Direct Cause
Chaos Theory
The Cogito Model
Compatibilism
Complexity
Comprehensive   Compatibilism
Conceptual Analysis
Control
Could Do Otherwise
Creativity
Default Responsibility
De-liberation
Determination
Determination Fallacy
Determinism
Disambiguation
Double Effect
Either Way
Emergent Determinism
Epistemic Freedom
Ethical Fallacy
Experimental Philosophy
Extreme Libertarianism
Event Has Many Causes
Frankfurt Cases
Free Choice
Freedom of Action
"Free Will"
Free Will Axiom
Free Will in Antiquity
Free Will Mechanisms
Free Will Requirements
Free Will Theorem
Future Contingency
Hard Incompatibilism
Idea of Freedom
Illusion of Determinism
Illusionism
Impossibilism
Incompatibilism
Indeterminacy
Indeterminism
Infinities
Laplace's Demon
Libertarianism
Liberty of Indifference
Libet Experiments
Luck
Master Argument
Modest Libertarianism
Moral Necessity
Moral Responsibility
Moral Sentiments
Mysteries
Naturalism
Necessity
Noise
Non-Causality
Nonlocality
Origination
Paradigm Case
Possibilities
Pre-determinism
Predictability
Probability
Pseudo-Problem
Random When?/Where?
Rational Fallacy
Refutations
Replay
Responsibility
Same Circumstances
Scandal
Science Advance Fallacy
Second Thoughts
Self-Determination
Semicompatibilism
Separability
Soft Causality
Special Relativity
Standard Argument
Supercompatibilism
Superdeterminism
Taxonomy
Temporal Sequence
Tertium Quid
Torn Decision
Two-Stage Models
Ultimate Responsibility
Uncertainty
Up To Us
Voluntarism

Philosophers

Mortimer Adler
Rogers Albritton
Alexander of Aphrodisias
Samuel Alexander
G.E.M.Anscombe
Anselm
Louise Antony
Thomas Aquinas
Aristotle
David Armstrong
Harald Atmanspacher
Augustine
J.L.Austin
A.J.Ayer
Alexander Bain
Mark Balaguer
Jeffrey Barrett
William Belsham
Henri Bergson
Isaiah Berlin
Bernard Berofsky
Robert Bishop
Susanne Bobzien
Emil du Bois-Reymond
Hilary Bok
George Boole
Émile Boutroux
F.H.Bradley
C.D.Broad
C.A.Campbell
Joseph Keim Campbell
Carneades
Ernst Cassirer
David Chalmers
Roderick Chisholm
Chrysippus
Cicero
Randolph Clarke
Samuel Clarke
Anthony Collins
Antonella Corradini
Diodorus Cronus
Jonathan Dancy
Donald Davidson
Mario De Caro
Democritus
Daniel Dennett
Jacques Derrida
René Descartes
Richard Double
Fred Dretske
John Dupré
John Earman
Laura Waddell Ekstrom
Epictetus
Epicurus
Herbert Feigl
John Martin Fischer
Owen Flanagan
Luciano Floridi
Philippa Foot
Alfred Fouilleé
Harry Frankfurt
Richard L. Franklin
Michael Frede
Carl Ginet
Nicholas St. John Green
H.Paul Grice
Ian Hacking
Ishtiyaque Haji
Stuart Hampshire
W.F.R.Hardie
William Hasker
R.M.Hare
Georg W.F. Hegel
Martin Heidegger
R.E.Hobart
Thomas Hobbes
David Hodgson
Shadsworth Hodgson
Ted Honderich
Pamela Huby
David Hume
Ferenc Huoranszki
William James
Lord Kames
Robert Kane
Immanuel Kant
Tomis Kapitan
Jaegwon Kim
William King
Christine Korsgaard
Andrea Lavazza
Keith Lehrer
Gottfried Leibniz
Leucippus
Michael Levin
George Henry Lewes
C.I.Lewis
David Lewis
Peter Lipton
John Locke
Michael Lockwood
E. Jonathan Lowe
John R. Lucas
Lucretius
James Martineau
Storrs McCall
Hugh McCann
Colin McGinn
Michael McKenna
Brian McLaughlin
Paul E. Meehl
Uwe Meixner
Alfred Mele
John Stuart Mill
Dickinson Miller
G.E.Moore
C. Lloyd Morgan
Thomas Nagel
Friedrich Nietzsche
John Norton
P.H.Nowell-Smith
Robert Nozick
William of Ockham
Timothy O'Connor
David F. Pears
Charles Sanders Peirce
Derk Pereboom
Steven Pinker
Plato
Karl Popper
Huw Price
H.A.Prichard
Hilary Putnam
Willard van Orman Quine
Frank Ramsey
Ayn Rand
Thomas Reid
Charles Renouvier
Nicholas Rescher
C.W.Rietdijk
Richard Rorty
Josiah Royce
Bertrand Russell
Paul Russell
Gilbert Ryle
Kenneth Sayre
T.M.Scanlon
Moritz Schlick
Arthur Schopenhauer
John Searle
Wilfrid Sellars
Henry Sidgwick
Walter Sinnott-Armstrong
J.J.C.Smart
Saul Smilansky
Michael Smith
L. Susan Stebbing
George F. Stout
Galen Strawson
Peter Strawson
Eleonore Stump
Richard Taylor
Kevin Timpe
Mark Twain
Peter van Inwagen
Manuel Vargas
John Venn
Kadri Vihvelin
Voltaire
G.H. von Wright
David Foster Wallace
R. Jay Wallace
W.G.Ward
Ted Warfield
Roy Weatherford
William Whewell
Alfred North Whitehead
David Widerker
David Wiggins
Bernard Williams
Ludwig Wittgenstein
Susan Wolf

Scientists

Michael Arbib
Bernard Baars
John S. Bell
Charles Bennett
Ludwig von Bertalanffy
Susan Blackmore
Margaret Boden
David Bohm
Niels Bohr
Ludwig Boltzmann
Emile Borel
Max Born
Walther Bothe
Hans Briegel
Leon Brillouin
Stephen Brush
Henry Thomas Buckle
Donald Campbell
Anthony Cashmore
Eric Chaisson
Jean-Pierre Changeux
Arthur Holly Compton
John Conway
E. H. Culverwell
Charles Darwin
Terrence Deacon
Max Delbrück
Abraham de Moivre
Paul Dirac
Hans Driesch
John Eccles
Arthur Stanley Eddington
Paul Ehrenfest
Albert Einstein
Hugh Everett, III
Franz Exner
Richard Feynman
Joseph Fourier
Michael Gazzaniga
GianCarlo Ghirardi
Nicolas Gisin
Paul Glimcher
Thomas Gold
A.O.Gomes
Brian Goodwin
Joshua Greene
Jacques Hadamard
Stuart Hameroff
Patrick Haggard
Augustin Hamon
Sam Harris
Martin Heisenberg
Werner Heisenberg
William Stanley Jevons
Pascual Jordan
Simon Kochen
Stephen Kosslyn
Ladislav Kovàč
Rolf Landauer
Alfred Landé
Pierre-Simon Laplace
David Layzer
Benjamin Libet
Hendrik Lorentz
Josef Loschmidt
Ernst Mach
Henry Margenau
James Clerk Maxwell
Ernst Mayr
Ulrich Mohrhoff
Jacques Monod
Wolfgang Pauli
Massimo Pauri
Roger Penrose
Steven Pinker
Max Planck
Susan Pockett
Henri Poincaré
Daniel Pollen
Ilya Prigogine
Hans Primas
Adolphe Quételet
Jerome Rothstein
David Ruelle
Erwin Schrödinger
Aaron Schurger
Claude Shannon
Herbert Simon
Dean Keith Simonton
B. F. Skinner
Roger Sperry
Henry Stapp
Tom Stonier
Antoine Suarez
Leo Szilard
William Thomson (Kelvin)
Peter Tse
John von Neumann
Daniel Wegner
Steven Weinberg
Paul A. Weiss
Norbert Wiener
Eugene Wigner
E. O. Wilson
H. Dieter Zeh
Ernst Zermelo
Wojciech Zurek

 
Necessity
Necessity is the idea that everything that has ever happened and ever will happen is necessary, and can not be otherwise. Necessity is often opposed to chance and contingency. In a necessary world there is no chance. Everything that happens is necessitated.
The great atomist Leucippus stated the first dogma of determinism, an absolute necessity.
"Nothing occurs at random, but everything for a reason and by necessity."
But we must distinguish between this claim of physical necessity and the simpler logical necessity of formal systems.

Aristotle's logic defended the logical necessity that only one of two contradictory statements can be true, and the other false. Diodorus Cronus developed the Master Argument to show that only one answer to a question about a future event can be true. Either Yes or No. This led to the Megarian idea of actualism, that there is no future contingency and only one possible future.

Diodorus' paradox was the result of the principle of bivalence or the law of the excluded middle. Only one of two logically contradictory statements can be necessarily true. Aristotle solved the paradox by saying that the truth of statements about the future is contingent on the actual future, as follows,
"A sea battle must either take place tomorrow or not,
but it is not necessary that it should take place tomorrow,
neither is it necessary that it should not take place,
yet it is necessary that it either should or should not
take place to-morrow."
(De Interpretatione IX, 19 a 30)

The major founder of Stoicism, Chrysippus, took the edge off strict necessity. Like Democritus, Aristotle, and Epicurus before him, Chrysippus wanted to strengthen the argument for moral responsibility, in particular defending it from Aristotle's and Epicurus's indeterminate chance causes. Whereas the past is unchangeable, Chrysippus argued that some future events that are possible do not occur by necessity from past external factors alone, but might depend on us. We have a choice to assent or not to assent to an action.

Later, Leibniz distinguished two forms of necessity, necessary necessity and contingent necessity. This basically distinguished logical necessity from physical (or empirical) necessity.

In the eighteenth century debates about freedom and necessity (free will versus determinism), many thinkers distinguished a moral necessity from physical necessity. Moral necessity describes the will being (self) determined by an agent's reasons and motives. Extreme libertarians insisted on a will that was not determined by reasons, fearing that this implies pre-determinism, which it does not. In two-stage models of free will, indeterminism in the generation of alternative possibilities for action breaks the causal chain of determinism.

Chance is regarded as inconsistent with logical determinism and with any limits on causal, physical or mechanical determinism.
Despite abundant evidence to the contrary, many philosophers deny that chance exists. If a single event is determined by chance, then indeterminism would be true, they say, and undermine the very possibility of certain knowledge. Some go to the extreme of saying that chance would make the state of the world totally independent of any earlier states, which is nonsense, but it shows how anxious they are about chance.
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)
The core idea of indeterminism is closely related to the idea of causality. Indeterminism for some is simply an event without a cause. But we can have an adequate causality without 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 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.
Necessity is critical for the question of free will. Strict necessity 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 potential alternatives.
The departure required from strict necessity is very slight compared to the miraculous ideas associated with the "causa sui" (self-caused cause) of the ancients.
Despite David Hume's critical attack on the necessity of causes, many philosophers embrace causality strongly. Some even connect it to the very possibility of logic and reason. And Hume himself strongly, if inconsistently, believed in necessity while denying causality. He said "'tis impossible to admit any medium betwixt chance and necessity."
Even in a world with chance, macroscopic objects are determined to an extraordinary degree. This is the basis for physical necessity. 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. Our actions are determined by our thoughts. But our thoughts themselves are free. This means that our actions were not pre-determined from before we began thinking.
we see a world of
soft causality and adequate determinism
We call this kind of determinism (determined but not pre-determined) "adequate determinism." Physical determinism is adequate enough for us to predict eclipses for the next thousand years or more with extraordinary precision.
The presence of quantum uncertainty leads some philosophers to call the world indetermined. But indeterminism is misleading, with strong negative connotations, when most events are overwhelmingly "adequately determined."
There is no problem imagining that the three traditional mental faculties of reason - perception, conception, and comprehension - are for all practical purposes carried on deterministically in a physical brain where quantum events do not interfere with normal operations, unless the agent deliberately seeks to be original and creative.
There is also no problem imagining a role for chance 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 which are the source of novel ideas.
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. Chance in the Micro Mind is the "free" in free will and the source of human creativity. The adequately determined Macro Mind is the "will" in free will that de-liberates, choosing actions for which we can be morally responsible.
[Necessity must be limited to its proper use in logic, and disambiguated from its close relatives causality, determinism, certainty, and predictability.]
For Teachers
For Scholars

Chapter 3.7 - The Ergod Chapter 4.2 - The History of Free Will
Part Three - Value Part Five - Problems
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