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Philosophers

Mortimer Adler
Rogers Albritton
Alexander of Aphrodisias
Samuel Alexander
William Alston
Anaximander
G.E.M.Anscombe
Anselm
Louise Antony
Thomas Aquinas
Aristotle
David Armstrong
Harald Atmanspacher
Robert Audi
Augustine
J.L.Austin
A.J.Ayer
Alexander Bain
Mark Balaguer
Jeffrey Barrett
William Belsham
Henri Bergson
George Berkeley
Isaiah Berlin
Richard J. Bernstein
Bernard Berofsky
Robert Bishop
Max Black
Susanne Bobzien
Emil du Bois-Reymond
Hilary Bok
Laurence BonJour
George Boole
Émile Boutroux
F.H.Bradley
C.D.Broad
Michael Burke
C.A.Campbell
Joseph Keim Campbell
Rudolf Carnap
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
Gottlob Frege
Peter Geach
Edmund Gettier
Carl Ginet
Alvin Goldman
Gorgias
Nicholas St. John Green
H.Paul Grice
Ian Hacking
Ishtiyaque Haji
Stuart Hampshire
W.F.R.Hardie
Sam Harris
William Hasker
R.M.Hare
Georg W.F. Hegel
Martin Heidegger
Heraclitus
R.E.Hobart
Thomas Hobbes
David Hodgson
Shadsworth Hodgson
Baron d'Holbach
Ted Honderich
Pamela Huby
David Hume
Ferenc Huoranszki
William James
Lord Kames
Robert Kane
Immanuel Kant
Tomis Kapitan
Jaegwon Kim
William King
Hilary Kornblith
Christine Korsgaard
Saul Kripke
Andrea Lavazza
Keith Lehrer
Gottfried Leibniz
Leucippus
Michael Levin
George Henry Lewes
C.I.Lewis
David Lewis
Peter Lipton
C. Lloyd Morgan
John Locke
Michael Lockwood
E. Jonathan Lowe
John R. Lucas
Lucretius
Alasdair MacIntyre
Ruth Barcan Marcus
James Martineau
Storrs McCall
Hugh McCann
Colin McGinn
Michael McKenna
Brian McLaughlin
John McTaggart
Paul E. Meehl
Uwe Meixner
Alfred Mele
Trenton Merricks
John Stuart Mill
Dickinson Miller
G.E.Moore
Thomas Nagel
Friedrich Nietzsche
John Norton
P.H.Nowell-Smith
Robert Nozick
William of Ockham
Timothy O'Connor
Parmenides
David F. Pears
Charles Sanders Peirce
Derk Pereboom
Steven Pinker
Plato
Karl Popper
Porphyry
Huw Price
H.A.Prichard
Protagoras
Hilary Putnam
Willard van Orman Quine
Frank Ramsey
Ayn Rand
Michael Rea
Thomas Reid
Charles Renouvier
Nicholas Rescher
C.W.Rietdijk
Richard Rorty
Josiah Royce
Bertrand Russell
Paul Russell
Gilbert Ryle
Jean-Paul Sartre
Kenneth Sayre
T.M.Scanlon
Moritz Schlick
Arthur Schopenhauer
John Searle
Wilfrid Sellars
Alan Sidelle
Ted Sider
Henry Sidgwick
Walter Sinnott-Armstrong
J.J.C.Smart
Saul Smilansky
Michael Smith
Baruch Spinoza
L. Susan Stebbing
Isabelle Stengers
George F. Stout
Galen Strawson
Peter Strawson
Eleonore Stump
Francisco Suárez
Richard Taylor
Kevin Timpe
Mark Twain
Peter Unger
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
Timothy Williamson
Ludwig Wittgenstein
Susan Wolf

Scientists

Michael Arbib
Bernard Baars
Gregory Bateson
John S. Bell
Charles Bennett
Ludwig von Bertalanffy
Susan Blackmore
Margaret Boden
David Bohm
Niels Bohr
Ludwig Boltzmann
Emile Borel
Max Born
Satyendra Nath Bose
Walther Bothe
Hans Briegel
Leon Brillouin
Stephen Brush
Henry Thomas Buckle
S. H. Burbury
Donald Campbell
Anthony Cashmore
Eric Chaisson
Jean-Pierre Changeux
Arthur Holly Compton
John Conway
John Cramer
E. P. Culverwell
Charles Darwin
Terrence Deacon
Louis de Broglie
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
R. A. Fisher
Joseph Fourier
Lila Gatlin
Michael Gazzaniga
GianCarlo Ghirardi
J. Willard Gibbs
Nicolas Gisin
Paul Glimcher
Thomas Gold
A.O.Gomes
Brian Goodwin
Joshua Greene
Jacques Hadamard
Patrick Haggard
Stuart Hameroff
Augustin Hamon
Sam Harris
Hyman Hartman
John-Dylan Haynes
Martin Heisenberg
Werner Heisenberg
John Herschel
Jesper Hoffmeyer
E. T. Jaynes
William Stanley Jevons
Roman Jakobson
Pascual Jordan
Ruth E. Kastner
Stuart Kauffman
Simon Kochen
Stephen Kosslyn
Ladislav Kovàč
Rolf Landauer
Alfred Landé
Pierre-Simon Laplace
David Layzer
Benjamin Libet
Seth Lloyd
Hendrik Lorentz
Josef Loschmidt
Ernst Mach
Donald MacKay
Henry Margenau
James Clerk Maxwell
Ernst Mayr
Ulrich Mohrhoff
Jacques Monod
Emmy Noether
Howard Pattee
Wolfgang Pauli
Massimo Pauri
Roger Penrose
Steven Pinker
Colin Pittendrigh
Max Planck
Susan Pockett
Henri Poincaré
Daniel Pollen
Ilya Prigogine
Hans Primas
Adolphe Quételet
Juan Roederer
Jerome Rothstein
David Ruelle
Erwin Schrödinger
Aaron Schurger
Claude Shannon
David Shiang
Herbert Simon
Dean Keith Simonton
B. F. Skinner
Roger Sperry
Henry Stapp
Tom Stonier
Antoine Suarez
Leo Szilard
William Thomson (Kelvin)
Peter Tse
Heinz von Foerster
John von Neumann
John B. Watson
Daniel Wegner
Steven Weinberg
Paul A. Weiss
John Wheeler
Wilhelm Wien
Norbert Wiener
Eugene Wigner
E. O. Wilson
H. Dieter Zeh
Ernst Zermelo
Wojciech Zurek

Presentations

Biosemiotics
Free Will
Mental Causation
James Symposium
 
Ilya Prigogine

Ilya Prigogine was a Belgian physical chemist who won the Nobel prize for investigating the irreversibility of processes in complex physical systems that are far from equilibrium conditions.

The physics equations describing classical dynamical motions are time reversible. One can replace the time variable t by negative time -t in the equations (reversing the time) and they remain equally valid. For example, if time were reversed, the earth would revolve around the sun in the opposite direction, but that seems quite acceptable.

However, many everyday processes cannot be reversed. If time were reversed, the steam (visible as water vapor) coming out of a kettle boiling water on the stove would instead go back into the kettle. It would look like a film played backwards. With time reversed, a glass shattering on the floor would miraculously reassemble its shards flying in all directions and rise back up onto the table. No such processes are ever seen in nature.

Prigogine's main research was to study the irreversibility of these processes.

It is now generally recognized that in many important fields of research a state of true thermodynamic equilibrium is only attained in exceptional conditions. Experiments with radioactive tracers, for example, have shown that the nucleic acids contained in living cells continuously exchange matter with their surroundings. It is also well known that the steady flow of energy which originates in the sun and the stars prevents the atmosphere of the earth or stars from reaching a state of thermodynamic equilibrium.

Obviously then, the majority of the phenomena studied in biology, meteorology, astrophysics and other subjects are irreversible processes which take place outside the equilibrium state.

These few examples may serve to illustrate the urgent need for an extension of the methods of thermodynamics so as to include irreversible processes.

Prigogine was unhappy with the work of Ludwig Boltzmann which showed how macroscopic irreversibility could arise from microscopic reversibility as a result of statistical considerations. To be sure, Joseph Loschmidt's reversibility paradox and Ernst Zermelo's recurrence paradox prevented Boltzmann's irreversibility from being anything but statistical.

He was also unhappy with classical dynamics, because Newton's equations are "time-reversible." He maintained that Erwin Schrödinger's deterministic wave function implied that even quantum mechanics is time reversible, which it is not. Quantum events lead to the "collapse of the wave function" which is irreversible.

Prigogine was awarded the Nobel Prize in 1977 for his contributions to non-equilibrium thermodynamics, particularly the theory of what he called "dissipative structures." These are physical or chemical systems in far from equilibrium" conditions that appear to develop "order out of chaos" and look to be "self-organizing." Like biological systems, matter and energy (of low entropy) flows through the "dissipative" structure. It is primarily the energy and negative entropy that is "dissipated."

This similarity to biological systems (in just one very important thermodynamic respect) was exploited by Prigogine to say he had discovered "new laws of nature" that could connect the natural sciences to the human sciences. Dissipation also implies irreversibility, a very important characteristic of life.

Prigogine had no physical explanation for irreversibility - beyond the fact that his physical "dissipative structures" and biological systems - exhibited it. He generally attacked classical Newtonian dynamics as being time reversible and thus providing no understanding of time. His understanding of time was based on the work of Henri Bergson and the uneven flow of time Bergson called "duration."

Prigogine discounts Boltzmann's work on the second law, which Eddington called the "Arrow of Time"
Prigogine believed that before him, there was "no direction of time, no distinction between past and future," because even quantum mechanics, in the form of Schrödinger's deterministic wave equation, could not do so (without invoking a collapse of the wave function). Prigogine introduced what he called a "third time" into physics - time as irreversibility. He saw non-equilibrium, dissipative systems far from equilibrium, as a new source of order giving to the system ill-defined "new space-time properties." ("The Meaning of Entropy," in Evolutionary Epistemology, p.63)

The Nobel committee noted the importance of irreversibility in living systems, and pointed out the work of Lars Onsager on nonlinear thermodynamics, years before Prigogine.

Classical thermodynamics has played a dominant role in the development of modern science and technology. In suffers, however, from certain limitations, as it cannot be used for the study of irreversible processes but only for reversible processes and transitions between different states of equilibrium.

Many of the most important and interesting processes in Nature are irreversible. A good example is provided by living organisms which consume chemical energy in the form of nutrients, perform work and excrete waste as well as give off heat to the surroundings without themselves undergoing changes; they represent what is called a stationary or steady state. The boiling of an egg provides another example, and still another one is, a thermocouple with a cold and a hot junction connected to an electrical measuring instrument.

The Onsager "reciprocity relations" and minimum entropy production
The first investigator who developed a method for the exact treatment of such problems, for example of the thermocouple, was Onsager who received the 1968 Nobel Prize for this contribution. His approach was, however based on assumptions which in principle make it applicable only to systems close to equilibrium.

The great contribution of Prigogine to thermodynamic theory in his successful extension of it to systems which are far from thermodynamic equilibrium. This is extremely interesting as large differences compared to conditions close to equilibrium had to be expected. Prigogine has demonstrated that a new form of ordered structures can exist under such conditions, and he has given them the name ''dissipative structures" to stress that they only exist in conjunction with their environment.

The most well-known dissipative structure is perhaps the so-called Benárd instability. This is formed when a layer of liquid is heated from below. At a given temperature heat conduction starts to occur predominantly through convection, and it can be observed that regularly spaced, hexagonal convection cells are formed in the layer of liquid. This structure is wholly dependent on the supply of heat and disappears when this ceases.

Quite generally it is possible in principle to distinguish between two types of structures: equilibrium structures, which can exist as isolated systems (for example crystals), and dissipative structures, which can only exist in symbiosis with their surroundings. Dissipative structures display two types of behaviour: close to equilibrium their order tends to be destroyed but far from equilibrium order can be maintained and new structures be formed.

The probability for order to arise from disorder is infinitesimal according to the laws of chance. The formation of ordered, dissipative systems demonstrates, however, that it is possible to create order from disorder. The description of these structures have led to many fundamental discoveries and applications in diverse fields of human endeavour, not only in chemistry. In the last few years applications in biology have been dominating but the theory of dissipative structures has also been used to describe phenomena in social-systems.

Classical thermodynamics, by contrast with nonlinear thermodynamics, can only be used for the study of reversible processes and systems in or near thermal equilibrium. Prigogine's "dissipative" systems, today more commonly known as complex systems, could be described as "self-organizing," a property that "emergentists" said was a basic property of life, one that could not be explained by "reductionist science.

Prigogine became very popular with "holists" and "vitalists" who were looking for new laws of nature.

Prigogine was a major member of the Brussels School of thermodynamics. The Santa Fe Institute in New Mexico is devoted to the study of complex systems in the natural sciences and the social sciences.

Prigogine is perhaps the most famous name in chaos theory and complexity theory. Although he made very few original contributions to these fields, he is famous for them, nevertheless. His work (especially his 1984 book written with Isabel Stengers, Order Out Of Chaos) is a major reference today for popular concepts like "self-organizing, "complex systems," "bifurcation points," "non-linearity,", "attractors," "symmetry breaking," "morphogenesis," "autocatalytic," "constraint," and of course "irreversibility," although none of these terms is originally Prigogine's. The name "dissipative structures" and perhaps the phrase "far from equilibrium" belong to Prigogine, but the thermodynamic concepts were already in Boltzmann, Bertalanffy, and Schrödinger, and perhaps many others.

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