Favourite quotations

This is a collection of favorite quotations, aphorisms and thoughts that have motivated and influenced my thinking. There is no particular order although there are certainly links among them.

Let the dataset change your mindset.
Hans Roslin

If you’re familiar with a principle you don’t have to be familiar with all of its applications.
Henry David Thoreau

Simplicity is the ultimate sophistication.
Leonardo da Vinci

The highest type of intelligence, says Aristotle, manifests itself in an ability to see connections where no one has seen them before, that is, to think analogically.
J. M. Coetzee

Johnny von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk.
Enrico Fermi

The spark of true poetry flashes when ideas are juxtaposed that no one has yet thought of bringing together.
J. M. Coetzee

It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.
Charles Darwin

There are living systems, there is no living matter.
Jaques Monod

In complexity, it is only simplicity that can be interesting.
Steven Weinberg

Bei Menschen, die wirklich leben, hört die Pubertät nie auf.
Martin Walser

Feedback: It is the fundamental principle that underlies all self-regulating systems, not only machines but also the processes of life.
Arnold Tustin, 1953

We need to overcome the idea, so prevalent in both academic and bureaucratic circles, that the only work worth taking seriously is highly detailed research in a speciality. We need to celebrate the equally vital contribution of those who dare to take what I call "a crude look at the whole".
Murray Gell-Mann, Nobel Laureate in Physics, 1994

I believe that theory is the antithesis of 'speculation', despite the confusion between the two in the minds of those who do speculate. Nor have I ever believed that theory and 'practice' were in any way adversarial. What I do believe is that 'practice,' in the form of observation and experiment, cannot constitute or replace theory, and that most of the basic questions of science, especially in Biology, fall quite outside the ken of 'practice', in the usual sense.
Robert Rosen

Understanding arises from reducing one type of reality into another.
Claude Levi-Strauss

I have always imagined that Paradise will be a kind of library.
Jorge Luis Borges

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful. If nature were not beautiful, it would not be worth knowing, and if nature would not worth knowing, life would not be worth living.
Henri Poincare

The only justification for our concepts is that they serve to represent the complex of our experiences; beyond this, they have no legitimacy.
Albert Einstein

Dealing with these system properties, which ultimately must underlie our understanding of all cellular behaviour, will require more abstract conceptualisations than biologists have been used to in the past. We might need to move into a strange more abstract world, more readily analysable in terms of mathematics than our present imaginings of cells operating as a microcosm of our everyday world.
Paul Nurse (Nobel Prize 2001), in Cell 2000

We feel clearly that we are only now beginning to acquire reliable material for welding together the sum total of all that is known into a whole; but, on the other hand, it has become next to impossible for a single mind fully to command more than a small specialized portion of it.
Erwin Schroedinger in 'What is Life?'

The post-genome challenge is to be able to interpret and use the genome data: focus is shifting from molecular characterisation to understanding of functional activity.
BBSRC newsletter, 1999

Organisms, cells, genes and proteins are complex structures of interdependent and subordinate components whose relationships and properties are largely determined by their function in the whole.

At the moment, biology remains a stubbornly empirical, experimental, observational science. The papers and books that define contemporary biology emanate mainly from laboratories of increasingly exquisite sophistication, authored by virtuosi in the manipulation of laboratory equipment, geared primarily to isolate, manipulate, and characterise minute quantities of matter. Thus contemporary biology simply is what these people do; it is precisely what they say it is.
Robert Rosen in 'Life Itself'

Life is a relationship among molecules and not a property of any molecule.
Linus Pauling

The aim of science is not things in themselves but the relations between things; outside these relations there is no reality knowable.
Henri Poincare

The sense of the world must lie outside the world... What we cannot speak about we must remain silent about... What can be described can happen too, and what is excluded by the laws of causality cannot be described.
Ludwig Wittgenstein in 'Tractatus Logico-Philosophicus'

Considering the inconceivable complexity of processes even in a simple cell, it is little short of a miracle that the simplest possible model - namely, a linear equation between two variables - actually applies in quite a general number of cases.
Ludwig von Bertalanffy in 'General Systems Theory'

Thus even supposedly unadulterated facts of observation already are interfused with all sorts of conceptual pictures, model concepts, theories or whatever expression you choose. The choice is not whether to remain in the field of data or to theorize; the choice is only between models that are more or less abstract, generalized, near or more remote from direct observation, more or less suitable to represent observed phenomena.
Ludwig von Bertalanffy in 'General Systems Theory'

I may remark parenthetically that the modern apparatus of the theory of small samples, once it goes beyond the determination of its own specially defined parameters and becomes a method for positive statistical inference in new cases, does not inspire me with any confidence unless it is applied by a statistician by whom the main elements of the dynamics of the situation are either explicitly known or implicitly felt.
Norbert Wiener in 'Cybernetics'

As the complexity of a system increases, our ability to make precise and yet significant statements about its behaviour diminishes until a threshold is reached beyond which precision and significance (or relevance) become almost exclusive characteristics.
Lotfi Zadeh

There is nothing more practical than a good theory.
David Hilbert

As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.
Albert Einstein

Anyone can squash a bug but all professors of this world couldn't build one.
Arthur Schopenhauer

To function effectively, the system scientist must know a considerable amount about the natural world AND about mathematics, without being an expert in either field. This is clearly a prescription for career disaster in today's world of ultra-high specialization.
John L. Casti in 'Reality Rules'

We see an ever-increasing move toward inter and trans- disciplinary attacks upon problems in the real world [..]. The system scientist has a central role to play in this new order, and that role is to first of all understand ways and means of how to encode the natural world into "good" formal structures.
John L. Casti in 'Reality Rules'

Scientific theories deal with concepts - not reality. All theoretical results are derived from certain axioms by deductive logic. In physical sciences the theories are so formulated as to correspond in some useful way to the real world, whatever that may mean. However, this correspondence is approximate, and the physical justification of all theoretical conclusions is based on some form of inductive reasoning.
Athanasios Papoulis in 'Probability, Random Variables, and Stochastic Processes'

The quest for precision is analogous to the quest for certainty and both - precision and certainty are impossible to attain.
Karl Popper

All models divide naturally...into two a priori parts: one is kinematics, whose aim is to parameterize the forms of the states of the process under consideration, and the other is dynamics, describing the evolution in time of these forms.
Rene Thom

The brain is a wonderful organ. It starts working the moment you get up in the morning and does not stop until you get into the office.
Robert Frost

It follows that the word probability, in its mathematical acceptance, has reference to the state of our knowledge of the circumstances under which an event may happen or fail. With the degree of information we possess concerning the circumstances of an event, the reason we have to think that it will occur, or, to use a single term, our expectation of it will vary. Probability is the expectation founded upon partial knowledge.
George Boole

You've got to draw the line somewhere.
unknown (presumingly a statistician)

An idea which can be used once is a trick. If it can be used more than once it becomes a method.
G. Polya and S. Szego

A random variable is neither random nor variable; it is simply a function.
unknown but true

The assumption of randomness is another mode of abstraction, a constraint which will be satisfied in certain kinds of situations and which will fail to be satisfied in others.
Robert Rosen

That all our knowledge begins with experience, there is indeed no doubt ... but although our knowledge originates with experience, it does not all arise out of experience.
Immanuel Kant

Truth can never be told so as to be understood, and not believ'd.
William Blake

For the things we have to learn before we can do them, we learn by doing them.

You can only find truth with logic if you have already found truth without it.
G.K. Chesterton

Oft expectation fails and most oft there; Where most it promises, and oft it hits; Where hope is coldest and despair most fits.
William Shakespeare in 'All's Well That Ends Well'

Prediction is difficult, especially if it concerns the future.
Mark Twain

The physical laws, in their observable consequences, have a finite limit of precision.
Kurt Goedel

Inferences of Science and Common Sense differ from those of deductive logic and mathematics in a very important respect, namely, when the premises are true and the reasoning correct, the conclusion is only probable.
Bertrand Russel

Everything is vague to a degree you do not realize till you have tried to make it precise.
Bertrand Russell

All traditional logic habitually assumes that precise symbols are being employed. It is therefore not applicable to this terrestrial life but only to an imagined celestial existence.
Bertrand Russell

Everything is a matter of degree.
The Fuzzy Principle

Any useful logic must concern itself with Ideas with a fringe of vagueness and a Truth that is a matter of degree.
Norbert Wiener in 'Cybernetics'

This harmony that human intelligence believes it discovers in nature - does it exist apart from that intelligence? No, without doubt, a reality completely independent of the spirit which conceives it, sees it or feels it, is an impossibility. A world so exterior as that, even if it existed, would be forever inaccessible to us. But what we call objective reality is, in the last analysis, that which is common to several thinking beings, and could be common to all; this common part, we will see, can be nothing but the harmony expressed by mathematical laws.
Henri Poincare

What we can observe is not nature itself, but nature exposed to our method of questioning.
Werner Heisenberg

Alles, was im Weltall existiert, ist die Frucht von Zufall und Notwendigkeit.

Fuer einen Wissenschaftler is es heute unvorsichtig, das Wort "Philosophie", und sei es "Naturphilosophie", im Titel (oder auch nur Untertitel) einer Arbeit zu verwenden. Damit kann er sicher sein, dass die Wissenschaftler sie mit Misstrauen, die Philosophen bestenfalls mit Herablassung aufnehmen werden. Ich habe nur eine Entschuldigung, die ich jedoch fuer legitim halte: die Pflicht, die den Wissenschaftler heute mehr denn je auferlegt ist, ihre Fachdisziplin im Gesamtzusammenhang der modernen Kultur zu sehen und diese nicht nur durch technisch bedeutende Erkenntnisse zu bereichern.
Jacques Monod in 'Zufall und Notwendigkeit'

Wissen ist besser als Glauben.
unknown but true

Geheimnisse sind noch keine Wunder.

Was die Menschen wuenschen, glauben sie im allgemeinen gern.

Wer nichts weiss muss alles glauben.
Marie v Ebner-Eschenbach

Wir sehen in der Natur nicht Woerter, sondern nur Anfangsbuchstaben von Woertern, und wenn wir alsdann lessen wollen, so finden wir, dass die neuen sogenannten Woerter wiederum bloss Anfangsbuchstaben von anderen sind.
Georg Christian Lichtenberg

Nichts zu wissen is keine Schande, wohl aber nichts lernen zu wollen.

Nur eine Gesellschaft im Einklang mit der Natur ist eine Menschliche.
Die Gruenen, 1983

Schopenhauer's Spruch: "Ein Mensch kann zwar tun, was er will, aber nicht wollen, was er will", hat mich seit meiner Jugend lebendig erfuellt.
Albert Einstein

Politisches Denken ist kontrolliertes Tolerieren.
unknown but true

Der Mensch ist mehr als er von sich wissen kann.
Karl Jasper

Die Menschen, die den richtigen Weg gehen wollen, muessen auch von Irrwegen wissen.

Miss alles, was sich messen laesst, und mach alles messbar, was sich nicht messen laesst.
G. Galilei

The chicken probably came before the egg because it is hard to imagine God wanting to sit on an egg.

Man kann niemanden ueberholen, wenn man in seine Fusstapfen tritt.

If you are not confused about the world, you are not seeing it clearly.

He who can does. He who cannot teaches.
George Bernhard Shaw

What we cannot think we cannot think, therefore we also cannot say what we cannot think.
Bertrand Russel

It is never possible to step twice into the same river.

Knowledge is to certain extent a second existence.
Arthur Schopenhauer

So gab ich das Erzaehlen wieder auf. Weil die Wahrheit dessen, was man redet, das ist, was man tut, kann man das Reden auch lassen.
Bernhard Schlink in 'Der Vorleser'

Me - we.
Muhammed Ali

Wer, wie, was, warum; wer nicht fragt bleibt dumm.

To know that we know what we know, and that we do not know what we do not know, that is true knowledge.

Studierende gehen in der Regel nur auf Kunde aus und nicht auf Einsicht ... Das die Kunde ein blosses Mittel zur Einsicht ist, und an sich wenig oder gar kein Wert hat, faellt ihnen nicht ein.
Arthur Schopenhauer

Der Wechsel allein ist Bestaendigkeit.
Arthur Schopenhauer

Art is a lie that makes us realise truth.
Pablo Picasso

Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house.
Henri Poincare, 1913

Naive realism leads to physics, and physics, if true, shows that naive realism is false. Therefore naive realism, if true, is false; therefore is is false.
Bertrand Russell

The fact that we can describe the motions of the world using Newtonian mechanics tell us nothing about the world. The fact that we do, does tell us something about the world.
Ludwig Wittgenstein

Look abroad through Nature's range
Nature's mighty law is change.
Robert Burns

In science, each new point of view calls forth a revolution in nomenclature.
Friedrich Engels

Truth comes out of error more easily than out of confusion.
Francis Bacon

The purpose of models is not to fit the data, but to sharpen the questions.
Samuel Karlin


Technical skill is mastery of complexity, while creativity is mastery of simplicity.
Eric Christopher Zeeman