Conjectures and Refutations: The Growth of Scientific Knowledge

by Karl Popper

Conjectures and Refutations is one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history. It provides one of the clearest and most accessible statements of the fundamental idea that guided his work: not only our knowledge, but our aims and our standards, grow through an unending process of trial and error.

Genres: Philosophy, Science, Nonfiction, History, Politics, Classics, 20th Century

608 pages, Paperback

First published January 1, 1963

About the author

Sir Karl Raimund Popper, FRS, rose from a modest background as an assistant cabinet maker and school teacher to become one of the most influential theorists and leading philosophers. Popper commanded international audiences and conversation with him was an intellectual adventure—even if a little rough—animated by a myriad of philosophical problems. He contributed to a field of thought encompassing (among others) political theory, quantum mechanics, logic, scientific method and evolutionary theory.

Popper challenged some of the ruling orthodoxies of philosophy: logical positivism, Marxism, determinism and linguistic philosophy. He argued that there are no subject matters but only problems and our desire to solve them. He said that scientific theories cannot be verified but only tentatively refuted, and that the best philosophy is about profound problems, not word meanings. Isaiah Berlin rightly said that Popper produced one of the most devastating refutations of Marxism. Through his ideas Popper promoted a critical ethos, a world in which the give and take of debate is highly esteemed in the precept that we are all infinitely ignorant, that we differ only in the little bits of knowledge that we do have, and that with some co-operative effort we may get nearer to the truth.

Nearly every first-year philosophy student knows that Popper regarded his solutions to the problems of induction and the demarcation of science from pseudo-science as his greatest contributions. He is less known for the problems of verisimilitude, of probability (a life-long love of his), and of the relationship between the mind and body.

Popper was a Fellow of the Royal Society, Fellow of the British Academy, and Membre de I'Institute de France. He was an Honorary member of the Harvard Chapter of Phi Beta Kappa, and an Honorary Fellow of the London School of Economics, King's College London, and of Darwin College Cambridge. He was awarded prizes and honours throughout the world, including the Austrian Grand Decoration of Honour in Gold, the Lippincott Award of the American Political Science Association, and the Sonning Prize for merit in work which had furthered European civilization.

Karl Popper was knighted by Queen Elizabeth II in 1965 and invested by her with the Insignia of a Companion of Honour in 1982.

(edited from http://www.tkpw.net/intro_popper/intr...)

Reviews

[Anahita · Rating 5 out of 5]

In my final years of high-school, I encountered Popper's theory of the process of 'Conjectures and Refutations' when studying the epistemology of science, and subsequently referenced his work in an essay - yet my understanding of it at the time was highly superficial.

When writing my final year dissertation at university, in Biology, I found myself mining through scientific literature and trying to place the experiment in its wider context. I was confronted with an immense and initially overwhelming body of knowledge, and eager to understand what sort of human ability, thought, and spirit, drove its construction, I found myself returning to these high-school essays. I went to the library and picked up the book, which I read over the course of almost five months during which I was writing the dissertation.

It's a remarkably uplifting read that I'd recommend to any scientist, for it draws the scientific method back to its philosophical origins - those of traditionalism, empiricism, probability, falsifiability, and verification. Popper, like that of many great minds, has the ability to pin down concepts into exhaustively clear and thorough writing. Science, he proposes, isn't a result of an accumulation and aggregation of observation statements about the truths of our world, but is a process that identifies and draws on problems, inconsistencies, and myths, through which scientific theories arise and regenerate on discovery of contradictory evidence. Popper draws on the concepts of many other philosophers; he simultaneously propounds his own theses as well as takes the reader on a historical journey.

A beautiful read that makes one think, hard. As a layman with respects to Philosophy, this was truly a remarkable read, paved the way for future readings within the discipline, and I think it would bring a great deal perspective to anyone trading in 'knowledge' arena.

[Philippe Malzieu · Rating 5 out of 5]

Popper is a point of required passage for all those which are interested in sciences. But the originality is that the method Popper bracket with other sectors and particularly with the policy.
Classically we defined a science in a positive way. we choose an hypothesis, we accumulated experiments to check the veracity of its. There a completely opposite way is taken. We will imagine experiments to prove that this théory is false.
For exemple, the proposal is “all the swans are white”. If I adopt an empirical attitude, I go in all the garden of London and I accumulate the observations. I see only white swans, so I conclude the swans are white. If I adopt Popper's method, I will seek to refute this assertion. I will search a black swan. And after some time, I find a black swan. So the sentence "The swan are white" is false. It's really a reverse méthod. It's thus consists in being endangered. The best exemple, it is Einstein and the Eddington experiment. For him the light rays follow a curve when they are in a massive gravitational field. Many people contest it.Einstein said to a particular place in Africa, at one specific time, It's necessairy to take a photo. If it didn't show, the curve, Eistein said that his theory is false and he loosed it. Of course, relalivity resist at this falsification test.
It is with that we can define asciences. A good scientific assumption must be refutable obviously but also risked but it will be thus fertile.
This explains why psychanalysis is not a science. If dreamed is from Freud the expression of the driven back desire, I can refute while saying: and the nightmare? But Freud who has answer to all will say me that it is the expression with a conflict with the super-ego. The psychanalysis is not refutable, this is not a science.
The following point is the problem of the objectivity. Popper is formaly opposed to the Marxist thought developed by the second school of Frankfurt. For Horckheimer and Adorno, sciences pure do not exist. There are always hidden interests. Sciences is always partial. This will be amplified by Bourdieu, Ricoeur and Foucault.Popper refutes this approach. The necessity is to be the most objective as possible. It's an intersubjectivity without subject. The good question for him is well “What did you say?” and not “for which reason and of which right did you say that?"
The application to the political arena is very operative. The problem is not knowledge which controls but how to refute controlling them. Thus in his eyes, the only legitimate mode is which makes it possible to return its leaders. It is thus the superiority of the democracy.
Popper is a free personality, apart from any ideology. His thought fascinating me.

[Xander · Rating 3 out of 5]

Conjectures and Refutations (1963) is Karl Popper's extension of his original work The Logic of Scientific Discovery (1934; English version published in 1956). It is a collection of philosophical essays and adresses for audiences or the radio. In a sense, this book is nothing new under the sun, if you already know Popper's philosophy of science. This doesn't mean that it isn't interesting material, but it lacks the originality and impressiveness of Popper's first work.

So what is interesting about this book? First of all, it is very readable and - apart from some deep discussions on logic - easy to follow. This is a big pré. Popper doesn't just give an exposition of his own views, but meticulously describes the positions of his opponents.

This last point brings me to another interesting point: Popper, by clearly stating the problems and offering his as well as his opponents' views, gives the reader the chance to learn many new things or to see familiar topics from a different angle. For me, this is the most important reason for reading Conjectures and Refutations.

The book itself is composed of 21 chapters, stand alone and can therefore be read at will. At the same time, all the chapters are implicitly connected by the limited amount of themes that play a role in this book. This is a good choice of Popper, since it offers cohesion and makes it feel as a whole (instead of a loose collection of essays; something that happens, sadly, a bit too often).

For the rest of this review, I want to pick three chapters that impressed me and that stand for the main thesis of Popper's book; the rest of the book can be read on own terms (which I can happily recommend!).

1. In chapter 10, Popper explains his own - revolutionary - philosophy of science. From Plato to Kant, philosophers have searched for a logic that would offer us a tool by which to collect certain knowledge. This attempt has failed miserably, for a reason that is - with (Popper's) hindsight - as stupid as it is simplistic. It is logically impossible to positively prove a proposition by experience. Yet experience is the only source we have by which we can perceive the world we live in. This, by the way, is a breath of fresh (philosophical) air if one has read the works of Locke, Berkeley, Hume and Kant, who all tried to make abstract distinctions in order to solve the problem.

Popper cuts the Gordian knot by simply saying: give up all these difficult attempts. Science should proceed by trial and error. The scientist should pick the interesting problems; try to come up with an interesting theory (how he/she does this doesn't matter); deduce specific predictions from this theory; test these predictions with experiment and observation; and last but not least, give up the theory or hypothesis as soon as it is refuted. In other words: even though theories cannot be proven true, they can be falsified - and this falsifiability is the criterium by which we can distinguish science from pseudoscience (or superstition, or religion).

So, how does science grow? By scientists that try to come up with new theories that explain all the known (and relevant) facts. So this means that all theories can be called science? No, according to Popper, the scientist should only come up with theories that offer new predictions to test (by observation and/or experiment) and/or that offer an incorporation of seemingly unconnected theories or facts. So, when Newton came up with his theory of universal gravitation, he offered a synthesis of Copernicus' heliocentric model, Kepler's laws of planetary orbits and Galilei's law of free fall. This is, Popper would say, scientific growth. And when Einstein came up with general relativity, he incorporated Newton's mechanics into a bigger, more general theory. This is, Popper would say, scientific progress.

Popper clarifies in this chapter (in a more accessible way than in his Logic of Scientific Discovery, in my opinion) what scientific hypotheses are desirable and which aren't. According to Popper, there is a common misunderstanding when it comes to scientific theories. Most people think that scientific theories, since theories cannot be certainly true (i.e. the problem of induction), they should be probable. We should apply probability calculus to evalute theories and this will lead us to the most probable theory. But this is a fallacy! The probability of a theory is, according to Popper, inversely related to its content. Popper advocates hypotheses that are as specific as possible (i.e. exclude as much other states as possible). This means that the most interesting hypotheses are the most easily falsified (since they exclude so many alternate states).

In other words: the best scientific theories are the ones that are the most improbable! And this makes sense, since if the most probable theories are the best ones, they should have been discovered by now - after 3000 years of scientific search. Popper's clarifying insights are simply amazing!

2. In chapter 5, Karl Popper offers us his interpretation of the Presocratics. Besides offering a thorough, yet accissible, invesigation of all the ideas involved - and offering us the chance to learn about ancient Greek philosophy in a modern day book - Popper clearly outlines his - by now infamous - message of what constitutes the scientific method.

The Presocratics (especially the Ionian school) picked the most interesting problems and tried to come up with answers to these questions. They did this, and were the first to do this, in a unique way; a way that would in 17th century turn into the 'scientific method' and what Popper calls 'rational criticism'. The Presocratics openly criticized the then-current theories about the universe and trying to offer new theories that were improvements - in the sense that the criticized points were improved upon - to the former theories. In practice, this meant that the student was encouraged to offer an intelligent critique of his master's theories. In other words: students were encouraged to use their reason to criticize their master's ideas.

With Aristotle, this way of improvement, of science, was abruptly halted. Aristotle claimed that certain knowledge (episteme) was possible and that one could use his reason (logos) to discover this truth. Aristotle's philosophy overtook Greece and the rest is history (in a nutshell: the Romans adopted Aristotelianism; the muslims copied and improved his manuscripts; the christians in the Middle Ages adopted it as a dogma). This meant that another way of doing science became influential and widespread: arguing for argument's sake.

This, of course, led nowhere. And it is only in the 17th century, with Galilei, that the method of singling out particular problems and trying to build on work of predecessors becomes important again. And it is this method of doing science - using reason to criticize theories of predecessors and offering new, improved theories - that is the philosophical foundation of all the changes - for better or worse - that we have witnessed from the 17th century onwards. In that sense, Isaac Newton was less important than Galileo Galilei, and Charles Darwin was less important than Louis Pasteur. Newton and Darwin offered grand syntheses of (up to that point) loose strands of science; Galilei and Pasteur singled out specific problems, tried to offer interesting new theories and tried to test them with experiments and observations. A theory that doesn't lead to new predictions and/or unification of hitherto loose strands of knowledge, is, according to Popper, a bad theory. And it is this crucial way of thinking about science that has its roots in the Ionian school of Thales, Anaximander, Xenophanes and others.

3. The third and last point of interest I want to mention is Popper's revaluation of Immanuel Kant in chapter 7. In this chapter, Popper argues that Kant's Critique of Pure Reason - or better, Kant's whole philosophy - has been misunderstood by his contemporaries and heirs. More specifically, Kant's contemporary Schelling, and Heirs like Fichte and Hegel, have misrepresented Kant's transcendental idealism in order to promote their own versions of radical, Romantic idealism. This development has led to an unfortunate chain of events in Western philosophy, in the sense that existentialism and nihilism are direct offspring from this misrepresented Kantian idealism (something which Popper works out in chapter 8 as well).

So what's the matter here? Kant was impressed - just like ma ny of his contemporaries - with Newton's mechanics. Newton's theory was so succesful in explaining all of celestial mechanics, and was vindicated time and time again (for example, in explaining better the planetary orbits than Kepler did, and in leading to the discovery of hitherto unknown planets) that nobody could seriously doubt the truth of Newton's model. Yet, as David Hume showed, there is no way to positively prove any fact as certainly true - this is logically impossible. Kant was so impressed by and convinced of the truth of Newton's mechanics, that he saw a serious problem here. (Popper: and interesting problems, not inductive observations, are the driving force of science!).

So Kant built a new philosophical system in which he claimed that we, as subjects, continuously order, by means of categories like space, time and causality, the sensual input of the empirical world around us. In other words: we constitute our own world. This led Kant to the conclusion that the world we think we know - the empirical world - is only an imperfect resemblance of the world as it is in itself. This world as it is in itself - the transcendental, or noumenal world - is unknowable.

But, even though Kant postulated a whole new - and by definition unknowable - world, he did accept the empirical world as existing and as knowable (via science). According to Popper, this has been radically taken out of context by Romantic philosophers like Schelling and Hegel, who twisted Kant's transcendental (!!!) idealism into a racial idealism, which basically says that, since we constitute the world around us ourselves, this is all there is. If this is all intellectual dishonesty or 'just' sheer misunderstanding Popper doesn't tell, but there are contemporary reports that Kant argued against Schelling's abuse of his philosophy, so the evidence points in the direction of intellectual dishonesty.

What Popper implicitly states - and he does this in various chapters - that one cannot understand philosophy if one reads the works of the great philosophers. One has to know the contemporary PROBLEMS that these great minds tried to solve, in order to understand their works in a meaningful way. So in another chapter (chapter 2) Popper argues that Plato's theory of Forms is not understandable, unless one knows about the contemporary problems in arithmetic. (Arithmetic was unable to deal with irrational numbers, which led Plato to geometry. This, in effect, is the foundation of Euclid's infamous geometry. It is rumoured that the Pythagorean sect, that based their creed on arithmetic as a universal explanation of the universe ["Everything is numbers"], drowned someone who told the outside world about the inability of arithmetic to deal with rational numbers, thereby falsifying their whole creed).

So to sum up, Karl Popper argues that scientific growth only comes about by scientists focussing on interesting problems, coming up with new theories that lead to new predictions, trying to flasifiy these predictions with experiments and observations and dropping all refuted theories. In this way, science progresses by trial and error, conjectures and refutations, and this leads us ever closer to the truth. The key words here are: interesting problems, interesting problems, interesting problems. To understand science or philosophy, one has to understand the problems involved; otherwise one doesn't understand the true meaning of these works.

The above is the central message of Popper's philosophy and this is the main theme in Conjectures and Refutations. It is a wonderful collection of stand alone chapters, which all deal with different aspects of this common line of thought. Therefore, even though it is a collection of loose chapters, it is one whole. The only drawback is the lack of originality of the material. I do think that for some who is new to Popper's philosophy (or to philosophy in general), Conjectures and Refutations can be a better start than his original work The Logic of Scientific Discovery. This last work is much less accessible and deals with much more complex (logical) aspects.

The best, of course, would be to read both books and to look for online material as clarification (for example, Youtube has much to offer on interesting and relevant philosophical material; the change of medium [audio or video] can add a lot of insight to the material in books!).

[Omar nagib · Rating 5 out of 5]

what is the book all about?

it discusses epistemology(philosophy of knowledge), philosophy of science, logic, philosophy of language and politics.

every article is an independant article, which can be read separately.

the book's title "conjectures and refutations" is borrowed from one of the articles within this book, it stands for popper's philosophy of science and how science procedures, science stars from problems but not observations, a scientist propose a myth or conjecture or hypothesis from his mind to solve the problem, this is about "conjectures", and for "refutations", this is the way by which we can test the theory, by serious attempts to refute it, and to falsify it by observations, and if this "conjecture" passes
the test, it is held "tentatively", but still remains conjecture which may turns out to be wrong in possible future tests.

what's very notable about the book is popper's infintely lucid and clear writing-style, yet the words carry very deep meaning, his arguments are solid and convincing.

another notable thing in popper is that he clears up complex philosophical terms so that his work becomes accessible to both professional philosophers, and beginners(like me).

I like how popper is original, genius in looking at things from completely new prespective, and offering ingenious solutions, I like his critical attitude that he's able to challenge widespread beliefs(dogmas).

this book really has changed my intellectual life, and it encouraged me to ge the remaining of popper's works, everyone interested in these subjects must read it.

[Ben Chugg · Rating 5 out of 5]

The most influential book on my thinking thus far — this work is responsible for my Popperian Enlightenment. Popper expounds a simple thesis: we learn from trial and error. He illuminates the deep consequences of this theory, demonstrating its implications for institutional design, political and social reform, human psychology, scientific progress, the distinction between science and metaphysics, and the role of tradition. The groundbreaking idea at the core of the work is that we are not searching for solutions to our problems, we are searching for mechanisms by which we can continue to make progress. We (our theories, our morality, our values) are fallible; we cannot predict all consequences of our actions. It is thus imperative that we are able to course-correct, and learn from our experience. This is how knowledge is generated. This holds not only for individuals, but for societies more generally. This work should be read by everyone who is hoping to contribute to making a better world.

[Elliott Bignell · Rating 5 out of 5]

Here endeth my reading of Popper's quartet of book-scale works. This volume covers ground from the other three, primarily "The Logic of Scientific Enquiry", but also elements of "The Open Society (...)" It takes the form of a collection of presentation texts and papers discussing the earlier material, each of which is therefore a nice evening's read in its own right and can be taken independent of the rest.

It is not without reason that Popper is widely admired as the most important philosopher of the 20th Century. With the possible exception of Russell, there is none so clear in his prose, even in the English translation. Where he resorts to mathematics, he explains his terms and symbols in accessible terms. Moreover he has had a profound impact, with popularisers of science such as Richard Dawkins presenting his model of falsification as definitive of science. Of course, there remains discussion of this in philosophical and social-science circles, but the fact remains that scientists tend to be falsificationists and that Popper's model does what it says on the wrapper: It explains how science can make progress and yield knowledge of the world.

His work on the Open Society is perhaps less well known, but important in its own right. Popper had direct experience of fascism and communism, and I think his understanding of threats to liberal society indispensable. Moreover, he saw the philosophical roots to these ideologies and their evils - Hegel's notions of historicism. Both, unarguably, saw history as a process with an inevitable direction and outcome, and both to some extent elevated it to an article of faith. Perhaps it is no surprise, therefore, that the "End of History" has seen its own ends thwarted and democratic society in unprecedented political chaos 30 years after the victory of liberal capitalism.

Necessary reading. Start immediately.

[Paul · Rating 4 out of 5]

This is in places an extremely engaging and intriguing book. The history of philosophy Popper describes in the early chapters is fascinating, as is his chapter 15 demolishing Hegelian and Marxist dialectic; between Gilson and Popper I have a feeling of much stronger grip of the history of philosophy (where fortunately Gilson is strong where Popper is weak, i.e., medieval philosophy).

Let me quote from that chapter 15 a sentence out of a passage that I might take as a banner for the intellectual contribution I want someone most to bequeath to theology:

"This [sketchy reasoning by modern dialecticians] should emphasize that for anyone who wants to promote truth and enlightenment it is a necessity and even a duty to train himself in the art of expressing things clearly and unambiguously--even if this means giving up certain niceties of metaphor and clever double meanings." (p 322)

It is a shame that Popper was so clearly dismissive of the Catholic faith and its intellectual tradition; he could see only the abuses of the Middle Ages, which abounded just as do the errors of every age. In reality, I think Catholic theology is uniquely suited to debate along critical lines, and humanity would profit greatly if its dogmas and the world outside were to be pondered critically, rather than with the kind of fluffy metaphorical thinking and desire to avoid all criticism of authorities even when they clearly conflict and are in need of reconciliation and contradiction.

[Richard Newton · Rating 5 out of 5]

This collection of Popper's talks and papers contains a typical set of strident claims about knowledge and related matters, particularly in the areas of scientific discovery but not only. Popper weaves together philosophy, history of ideas and the history of science into a compelling mix. I enjoyed this far more than his Logic of Scientific Discovery. That latter book may contain a more definite argument for his views on science, but this book is much more approachable. And at times, Popper comes across as a warm and charming intellect, which does not always come across in other writings. I particularly enjoyed papers 5 and 11, and he has given me renewed interest in pre-Socratic philosophers, which previously I had tended to ignore as far to obscure to understand or take anything meaningful from.

[Mirek Kukla · Rating 5 out of 5]

Popper is brilliant. He's a terrific writer - his thoughts are original, yet is prose is clear and straightforward. With the exception of one or two boring essays, this collection is the shit. Check it out

[Illiterate · Rating 4 out of 5]

Popper revisits his philosophy of science relating it to other philosophical fields. Don’t miss: chap 10 on criteria growth.

[Derek · Rating 5 out of 5]

My brain wrinkled

[Jooseppi Räikkönen · Rating 3 out of 5]

This volume contains much of Popper's more approachable material in the form of lectures and writings intended for a more general audience. While good for clarity, this does mean a lot of repetition and unnecessarily inexact prose.
The best part of this volume - though helplessly outdated and falsified by further research in probability theory and mathematical logic - are the addenda. The worst are easily the parts which have anything to do with the history of philosophy, which he butchers even when viewing it in a favourable light.

[Helisa Taban · Rating 5 out of 5]

This book has given me a lot to think about. The most important lesson that I got from it is that a good scientific theory is very specific and seeks falsification. The problem with Freudian science, astrology, and other such broad theories is that they are vague and can be applied to almost everything. Everything can be interpreted with a pseudoscientific lens. Once someone believes in Marx or Freud, it is easy to view all human interactions as manipulated by bourgeois propaganda, or simply symptoms of Freud's idea of Fixation and the Oedipus Complex. That is not to say that these theories are necessarily false, but they tend to have a confirmation bias, and they are somehow always immune to being falsified. Observations in the real world easily confirm these theories, but Popper suggests that a good scientific theory MUST run the risk of falsification and should not be sought to be confirmed but be refuted instead. This approach could even be applied to social and political theories. An interesting case that occurred to me is the idea of biblical, Koranic, or other claims of scriptural miracles. It seems to be that it is always the real world that conforms to such beliefs, and not the other way around, but that can't be scientific. That is more like deluding ourselves by choosing to interpret the world the way we want to. According to Popper, the beliefs need to seek falsification, and should be refuted on the basis that they do not adequately describe the universe. This is also why he proposes the idea that contrary to the commonly accepted scientific method which begins with an observation and then a hypothesis and then the experiment, all scientific methods begin with a hypothesis first and then proceed to the observation stage. He suggests that no observation is made without a question or some prior conjecture. In fact, it is the hypothesis that actively seeks to observe and experiment, and not the other way around. To be most scientific, we should form conjectures, and then attempt to refute them and see how well they stand scrutiny. Great book! A must-read for anyone interested in science or philosophy, or both.

[Lord_Humungus · Rating 3 out of 5]

Review in English (not my mother tongue) and Spanish (below).

A set of essays on epistemology that can be read independently. When it came to understanding it, I had the advantage of having read a disciple of his, David Deutsch, who writes even more clearly. Actually, if you have already read a book by Deutsch, this book does not bring so many new important things.
I liked it a lot, but the part that interested me the most, that talks about the concepts of "probability", "verisimilitude", "empirical content", and "verification" was very difficult, partly due to lack of clarity in the exposition in those parts, and partly by a notation that is unfamiliar to me. I'll go back to those parts when I know more about probability.
Popper is a giant, and I was pleasantly surprised, because I did not expect it, that his conception of nationalism is very similar to mine: nationalism is absurd.

Un conjunto de ensayos sobre epistemología que se pueden leer de manera independiente. A la hora de entenderlo, yo contaba con la ventaja de haber leído a un discípulo suyo, David Deutsch, que escribe todavía más claramente. En realidad, si ya has leído algún libro de Deutsch, este libro no aporta tantas cosas importantes nuevas.
Me ha gustado bastante, pero la parte que más me interesaba, que habla de los conceptos de "probabilidad", "verosimilitud", "contenido empírico", y "verificación" era muy difícil, en parte por falta de claridad en la exposición, y en parte por una notación que no me es familiar. Volveré a esos ensayos cuando sepa más sobre probabilidad.
Popper es un gigante, y me gustó, porque no me lo esperaba, que su concepción del nacionalismo es muy similar a la mía: el nacionalismo es absurdo.

[Brian · Rating 4 out of 5]

Brilliant writer - very dense, intellectually complicated, and takes a long time to read. But if you're looking for a book that makes you feel smarter and examine life more critically and logically, then this book will help you along that path. Popper's primary argument is that science is not developed through carefully thought-out hypotheses, but by essentially random attempts at figuring things out (conjectures) and then attempts that prove them wrong (refutations).

He also argues that, basically, nothing can be scientifically proved - there's no such thing as a law, only a hypothesis. For example, the 'law' of gravity could be disproved by finding a planet in the universe that operated by different rules. A hypothesis cannot be proved with a thousand supporting examples, but can be disproved by a single contrary example. Those areas that do not work like this (psychology, etc.) are not sciences but pseudo-sciences.

Overall, great book but extremely philosophical and intellectual.

[Gnuehc Ecnerwal · Rating 4 out of 5]

One of the most challenging ideas from this book is to convince the general society to acknowledge that no amount of 'confirmative evidence' can validate a theory to the same extend as how one counter-example could invalidate a theory once and for all. We are socially conditioned not to rock the boat (argue and criticize), to trust the viewpoints of experts/elders/authority, and we are told that we have to prove our case with evidence or testimony from a trust-worthy source. Popper proposed that it is only through criticism and attempts to 'disprove' others' claims that drive the progress of knowledge. A fascinating idea that is worth contemplating and incorporating into our attitude towards all knowledge in general.

[Jim Mehnet · Rating 5 out of 5]

The first three essays are focused on what differentiates science from pseudo-science. Loved them. They have provided me with good set of tools to filter BS from science and set me on a new line of inquiry, the philosophy of science. Popper’s ideas on the strengths of demarcation, falsifiability, and the inadequacies of induction and confirmation are very convincing. As a non-philosopher I found some of the other essays a bit of a mixed bag, but those first three essays were great.

[David Withun · Rating 4 out of 5]

-

[Parker · Rating 5 out of 5]

Well damn I've been hoping to read something like this for awhile. Best I've read this year or longer. I've had the foggy intuition that obtaining true knowledge is both a myth and very important, but had never read Popper's explaination of why. True scientific knowledge can only be falsified by observation, not derived from it. And the implications of this explain so much about today...
The (Greek tradition) value science for us informative content and for it's ability to free our mind from old beliefs/prejudices/certainties. Science is not interested in the quest for (neither objective nor subjective) truth/certainty or establishing a theory as certain or probable. Only interested in criticising, hoping to find mistakes, learning from mistakes, and proceeding to better theories.


CRAZY AMOUNT OF NOTES--
Introduction:
Neither British empiricism nor Continental rationalism (senses vs intellect) can be sources of knowledge. Despite being part of the great movement of liberation that started the Renaissance and free societies, it relied on the (fallible) idea that the TRUTH is manifest and can reveal itself to those seaking it. Manifest truth: we hold these truths to be self evident. But we can always be wrong. Manifest/observable/empirical truth can be knowledge, but none has authority to be a source. It has to be continually checked for err.

"Knowledge can be only finite, while our ignorance must necessarily be infinite."

"the more we know about the world, and the deeper our learning, the more specific and articulate will be our knowledge of what we do not know, our knowledge of our ignorance"

Empiricism: observation is the ultimate source of knowledge. Empiricists ask, how do you know? What is the source of your knowledge? But they are appealing to an Authority.

Rationalism: logic is the only source of true knowledge.

Ch 1.CONJECTURE AND REFUTATION
Popper's fallibilism says it is our ability to be wrong and then show we are wrong and correct errors that creates knowledge, whittling away at the incorrect to point toward truth.

Pg51. Science cannot be demanded to achieve a narrow rational certainty, only the broad realm of rationality... And ultimately, be a method of trial and error to propose conjecture and refutation. -- the criterion of the scientific status of a theory is it's falsifiability, or refutability, or testability.

Also, a statement that makes high probability predictions is uninteresting because it says little and has no explanatory power.

2.NATURE OF PHILOSOPHICAL PROBLEMS
Beginning with axiomatic basic truths (infallible, prima facie) in philosophy cannot lead to understanding of the problems that inspired Plato, and then the Renaissance in science. No longer explaining the physical world by a pushed invisible world.

3. THREE VIEWS OF HUMAN KNOWLEDGE (Essentialism, Instrumentalism, Fallible Conjecture/Fallibilism)
Galileo was followed by hundreds of years as the church gradually accepted, then twisted natural philosophy into an instrumentalist view of science (science as an instrument only to make accurate observations based on hypothesis/tricks that say nothing on the true description of the real world). IE they turned a scientific theory back into a philosophical theory and retained ultimate authority over Truth. And this is still generally accepted by scientists everywhere. On the opposite side, rationalists (Greek tradition) value science for us informative content and for it's ability to free or mind from old beliefs prejudices certainties. And to offer new hypothesis conjecture in their place. BUT explanations by 'essence' are no better than instrumentalists. All Conjecture is Fallible. Essentialism = science will find the base level/essential reality to believe in and not question. Instrumentalism = scientific theories are merely instruments to build better and better instruments for predicting observations and relationships, but say nothing about ultimate truth and not the physical systems of our reality.

But whether science is descriptive (of essential truths) or instrumental is a psuedo-problem. Fallibilism = we should provide creative conjecture and then refute, and repeat.

4. RATIONAL THEORY OF TRADITION
Rationalists/skeptics say, I'm not interested in traditions and want to judge everything in it's own merit. But they can't escape their own traditions. So how can you analyze the scientific tradition and where it came from? Popper says it wasn't only the Greeks who tried to explain nature rationally: all myth makers do that. But the Greeks added the tradition of criticism, and challenging new myths to have better explanations.

Science is not about coming up with new myths, it's about being able to criticize myths to find better explanations. 2 ways science grows; (1) by accumulating knowledge in new volumes, (2) by eliminating bad explanations/traditions/and myths. The second is the important one, for the first alone cannot be different from accumulating more myths.

Socially traditions are required for people to know how to act, they are necessary regularities for us to be able to act rational in society, and don't depend on their particular merits or demerits. It's not possible to act rationally unless you know how the world should respond to you; children crave uniformity. Social sciences attempt to come up with social fact, just as the natural sciences attempt to explain nature and it's reactions to our actions. Social reformers that attempt to wipe out traditions (Platos 'canvas cleaners') and stay over with a new blue print simply start with a new set of traditions/myths. But you'll have a new complex system in need of criticism, not necessarily and better than our current one, that will take many years of study and experiment in a new social vacuum to know how we can better it. Why throw away all of our progress? Why not make it's better.

Language is a tradition and institution. We can use it to emote, signal, describe, but also argue. Modern enemies of reason can be both anti-traditional or traditional, but they try and destroy the argumentative. Instead telling on the emotive, self-expression (self_truth?)

5. PRESOCRATICS
Aniximander came up with the theory of the Earth bring equidistant from everything else and therefore motionless in it's position. This idea must have come as critical response to previous asymmetrical theories, because it can't be purely his primary observation that the Earth is a flat sided drum. In each of the next several generations the Greek find at least one genius new philosophy of cosmology based on their critiques and arguments of other theories. Their (rationalist) tradition of critical discussion enabled this. It is the ONLY practical way of expanding our (conjectural/hypothetical) knowledge.

10. TRUTH, RATIONALITY, AND THE GROWTH OF SCIENTIFIC KNOWLEDGE
A.(GROWTH). Science starts from problems, and not from observations. A scientific theory is an attempt to solve a problem (concerned with discovering an explanation). The goal is to over throw current theory and replace with a more explanatory one. Rejecting all available theories is scientific growth and the only way to make better explanations, so science has to grow to be science. A statement that explains more (i.e. explains both a and b, not just a) is less probable be definition: [p(a)>p(ab)]. And a less probably explanation is more easily tested/refuted. Only a highly testable theory is worth testing. Therefore, we must be looking for less likely explanations because they explain more, are more predictive of unexpected/unexplained observations, solve more problems. Science starts with problems, not observations.
B.(TRUTH).
There are many forms of truth/facts (theories of objective truth say truth always "corresponds" to facts, while theories of subjective truth say truth is a property of our state of mind (beliefs) and that facts are mere instruments for understanding these states of mind. Subjective theories of truth are irrefutable: everything they say about the world can be replaced with a belief statement (snow is white, can be replaced with I believe the snow is white).
C.(Truth-Content)
Science is not interested in the quest for certainty or establishing a theory as certain or probable. Only interested in criticising, hoping to find mistakes, learning from mistakes, and proceeding to better theories. Versimilitude, or truth approximation, shows we can say theory 1 is less wrong than theory 2, even if both end up being wrong. T2 passed more severe tests, which T1 failed.
D.(Background Knowledge and Growth)
E.(3 Requirements for Knowledge Growth)
1.Requirement of simplicity says a new theory should find a new simple way to unify/connect ideas or previously unrelated facts.
2. Independent testable, and not ad hoc-produced after the test was complete.
3. Must pass a new severe test.

REFUTATIONS
11. Science vs Metaphysics (and it's demarcation)
This demarcation cannot rely on the senses (to demarc nonsense), but most rely on its falsifiability.

Bacon said metaphysics operated byl) mental anticipating (like hypothesis).

14. Prediction and Prophecy in Social Sciences.
A criticism of historicism (unravelling the plot of mankind will hold the key to the future, predict and avoid apocalypse, etc. Who authors this plot?), and specifically Marxism.
Scientific prediction relies on variable conditions, eg when a water boils relies on its changing temperature. "The main usefulness of physical science is not the prediction of mechanical system like eclipse: and social sciences do not need to make predictions/prophecy.
No need to hate reason just because social sciences can't make prediction. Task of social sciences: hello us understand the consequences of our actions, and help choose our actions, correct our errors more wisely.
Social sciences cannot: (1) study and predict group/classes/societies behavior holistically (2) describe, as a conspiracy theory, the results of society a direct design of powerful individuals and groups.

18. Utopia and Violence
All ends at irrational. Only means can be rational. Rationalism is argument, not violence. Utopia and it's blueprint is an ideal that cannot be questioned, therefore a dogmatic end which can be justified by any means. But there's nothing won't with political ideals that work toward eliminating error through rationalism, but just focusing on one abstract Utopian ideal is fatal toward tyranny.
-don't sacrifice today's misery for tomorrow's promised Utopia. Potential future happiness cannot be predicted, today's misery is real. Our actions must be ends to eliminate misery today. It's easy to agree across the lines on what constitutes an intolerable evils of society, and we can make progress on arguing toward them. Ideal Utopias are prophecy, and opposite, and by definition irrational first principals.

19. Our Time.
Five thesis on our time:
History: the Renaissance and the Reformation is the conflict between the idea is the truth being manifest (an open book-first the Bible, then book of Nature- we just need to read) and that truth is hidden (discernable only by deciphering God's will be an Authority).

[Jimi Olaoya · Rating 4 out of 5]

I picked this up at my local Japanese bookshop since I have seen Karl Poppers work referenced by authors that I have been reading from recently like David Deutsch and Nassim Taleb. His idea of falsifiability as the criterion of demarcation is super simple yet powerful: a theory must be open to being proven wrong to count as science. What stood out is how this applies beyond physics to fields like politics and economics.
His view on trial and error also resonated.

Stronger theories are more exposed to criticism because they cover more ground and make bolder claims. This does not make them weaker, it makes them better. Einsteins theory replaced Newtons because it explained more, covered more variables and stood up to greater scrutiny. Now this does not mean Newtons theories are suddenly invalid but they were a stepping stone that paved the way for Einstein. Of course as a consequence of this idea it means Einsteins theories are also tentative in a sense since if a better explanatory theory comes along it replaces his theory too at it was simply the best theory for the moment.

Some parts were tough to follow, especially when he referenced older thinkers. Since it is a collection of essays, the flow is not always smooth, but the key ideas come through. Some essays repeat the same ideas in different ways, but this repetition helps reinforce the concepts.
Popper challenges ideas such as inductivism, empiricism etc. This book clarified what science really is: not an absolute truth or unquestionable authority, but a process of making conjectures and exposing them to criticism. It is always provisional and open to revision.
He even questions the dialectical school of thought, which tries to evade criticism by absorbing it in a way that avoids genuine refutability, a subtle but important distinction from his own emphasis on open criticism.

He also dives into the role of language and logic in gaining insight about the world. This part was quite fascinating having learned a new language later in life I was absorbed in the theoretical aspects of how language maps to reality.
it seems to be a combination of reason, observation that results in explanatory power of theories. His engagement with figures like Bacon and Kant is sharp and thought provoking.

Overall for me the key takeaway amongst many which I can’t think of at the moment is is this: to get closer to truth which is by no means manifest, we need three things:
1. imagination,
2. trial and error
3. the gradual discovery of our prejudices through imagination, trial and error, and critical discussion.

[Daniel Hageman · Rating 4 out of 5]

Popper substantiates (a word he would probably hate based on the definition, but also who cares about definitions, right? ;) ) himself as a thinker worthy of any serious intellectual's time and reading list. My own level of convergence with him and his ideas remains fickle depending on the topic, but I continue to have access to a close group of friends who have studied him in great depth and continue to share their insights. Popper's framing of problem solving, pragmatics in societal progress, and the growth of knowledge is something that makes even the most fervent hedonist want to ascribe some intrinsic value to these ideas that often do not fall short of inspiring. Looking forward to re-reading much of this book along with his many other works!

[clamintine · Rating 5 out of 5]

Exceptional

هو راديكالي اوي و عكس Adorno في حتة مدّ فكرة الـ empirical attitude للسياسة.
Great account on falsification and refutability as well

[Mark Scott]

Karl Popper was a rationalist of two phrases: trial and error and give and take. Popper liked argument; or, he liked to argue. “A rationalist, as I use the word, is a man who attempts to reach decisions by argument and perhaps, in certain cases, by compromise, rather than by violence. He is a man who would rather be unsuccessful in convincing another man by argument than successful in crushing him by force, by intimidation and threats, or even by persuasive propaganda” (Con and Ref, 356).

Popper didn’t like being disagreed with. In writing about Popper’s fierceness in this regard, Bryan Magee noted that Popper never spoke again to an Israeli student of his who criticized him in a book review. I think that student got his revenge. His name was XXX.

“By argument and perhaps, in certain cases, by compromise”: there was Popper admitting his reluctance to compromise, his preference for being convincing “by argument.” There wasn’t much other than argument for Popper, however often he insisted on the reality of an external world. And as often as he dismissed arguments over the meaning of words, Popper was careful to define the term “rationalist.”

Can what Popper called “the attitude of reasonableness” (C&R 356) be plotted on the violence graph?

In “What is Dialectic?” Popper wrote in his fifth footnote:

In Hegel’s terminology, both the thesis and the antithesis are, by the synthesis, (1) reduced to components (of the synthesis) and they are thereby (2) cancelled (or negated, or annulled, or set aside, or put away) and, at the same time, (3) preserved (or stored, or saved, or put away) and (4) elevated (or lifted to a higher level). The italicized expressions are renderings of the four main meanings of the one German word ‘aufgehoben’ (literally ‘lifted up’) of whose ambiguity Hegel makes much use (C&R 314).

And of Hegel’s much-made-use-of aufgehoben’s ambiguity, Heidegger, Derrida, and numerous others had made much further use by 1963, when Conjectures and Refutations: The Growth of Scientific Knowledge, was first published. (It was revised and published a second [1965] and a third time [1969].) “What is Dialectic?” was a paper read to a philosophy seminar at Canterbury University College, Christchurch, New Zealand, in 1937, and printed in Mind, N. S., 49, in 1940.

Popper’s first language was German. In English, he kept being misunderstood and misinterpreted by other philosophers. Historically, he said, all philosophers have been used to misunderstanding. He did’t say that; he said, used to being misunderstood. Popper probably nowhere admitted that he himself was used to misunderstanding philosophers. He nowhere conjectured that philosophy was a using to misunderstand, a method of misunderstanding.

Contradictions, Popper said, “are extremely fertile” (CR 316). For “fertile,” I read “futile.” I might have read “feral.” No, Popper said, that was “nothing better than a loose and wooly way of speaking” (CR 316). Contradictions were “extremely fertile” if only we refused to “put up with” them. If we accept them, “then they will be barren, and rational criticism, discussion, and intellectual progress will be impossible” (CR 317). Popper’s metaphor was sexual: we should choose to be fruitful and multiply. But he didn’t develop that metaphor. He turned instead to laws of logic and “rules of inference” (317), and criticized the way “dialecticians” use and take “much too seriously” “a number of metaphors”:

An example is the dialectical saying that the thesis ‘produces’ its antithesis. Actually it is only our critical attitude which produces the antithesis, and where such an attitude is lacking—which often is the case—no antithesis will be produced. Similarly, we have to be careful not to think that it is the ‘struggle’ between a thesis and its antithesis which ‘produces’ a synthesis. The struggle is one of minds; and these minds must be productive of new ideas: there are many instances of futile struggles in the history of human thought, struggles which ended in nothing. And even when a synthesis has been reached, it will usually be a rather crude description of the synthesis to say that it ‘preserves’ the better parts of both the thesis and the antithesis (CR 315).

In being “careful” about metaphors, Popper wasn't being careful. In every instance, he preserved the metaphor he was criticizing. His target wasn’t a carelessness with metaphor in his opponents, but their reluctance to specify an agent or agency of production, struggle, and preservation. Who or what does the act, not the mode or method, not how the act is done, got Popper’s correction. After all, as a proponent of fertility, he couldn’t do without “production,” which was here synonymous with conception, gestation, and birth. What does the producing? “Minds” do, not words, concepts, or propositions called “thesis” and “antithesis.” Mind was the womb Popper wanted the dialecticians to have been careful about. People were missing from the dialectical equation, and Popper missed them. “Minds” was his metonymy for men and women, for thinkers, for those who use language to make arguments. A materialist, a rationalist, an objectivist, a methodist of the humanist school, Popper attacked the way materialists of the materialism school talked about the reproductive process. It wasn’t only a matter of preferring fertility to futility; it was a matter of preferring minds to Marxism, democracy to determinism.

In this connection, Popper’s philosophy of the growth of scientific knowledge was the foundation of whatever politics he was supposed to have espoused, just as Kenneth Boulding’s critique of dialectical materialism, which he developed during his year in Japan in 1954, and later elaborated in his Primer on Social Dynamics (1970), grew out of his habits as an economist.

Popper, Boulding, Peirce, Whitehead, Emerson, and Einstein all began with one big theory of the universe; and though they descended reluctantly into particulars, they never omitted to do so. Popper thought that the two greatest men of his time were Einstein and Churchill. Boulding named one of his certainties “the bathtub theorem”; Whitehead, one of his, “the fallacy of misplaced concreteness.” Emerson said, “The whole value of the dime is in knowing what to do with it.” Einstein wrote of clocks and trains, of lights, ships, and a fired bullet, to make his theory of special relativity understood. And as for Peirce, Popper quoted what he called “one of Peirce’s brilliant comments” (I quote Popper as he quotes Peirce):

. . . one who is behind the scenes (Peirce speaks here as an experimentalist) . . . knows that the most refined comparisons [even] of masses [and] lengths, . . . far surpassing in precision all other [physical] measurements, . . . fall behind the accuracy of bank accounts, and that the . . . determinations of physical constants . . . are about on a par with an upholsterer’s measurements of carpets and curtains . . . . (OK 212–13; from Peirce, Collected Papers 6: 35).

Peirce produced Popper; but first, in New England, Peirce produced P. W. Bridgman, who was obsessed with physical operations, and with the description of them, and with the measurement of them; and who was baffled by the way scientists talked about what they did as scientists, and by how others wrote about what scientists did, and thought.

Karl R. Popper produced struggles that preserved the productions that preserved the struggle for “intellectual progress” (317).

Popper’s problem wasn’t metaphors or production. It was what certainties to begin with, such that there was and would be no contradiction, as there seemed on the face of it to be, between the “strict Newtonian laws” and the “laws of chance” that both he and Peirce—men of “the same kidney,” to use a Peirce phrase—believed in. Hence “the most important misunderstandings and muddles arise out of the loose way in which dialecticians speak about contradictions,” Popper said (CR 316). They—Popper named no names—speak about them in a way that “amounts to an attack upon” a “law” of “traditional logic,” “a law which asserts that two contradictory statements can never be true together.” The dialecticians claimed to have a new logic, one that was “at the same time a logical theory and (as we shall see) a general theory of the world.” Nothing in it, Popper declared, “nothing better than a loose and wooly way of thinking” (CR 316).

Popper stood against “having it both ways”; he stood against “mysterious force.” Popper stood for “resolution”; he stood for full explanation; he stood for “one of the few facts of elementary logic which are not quite trivial, and deserve to be known and understood by every thinking man.” He stood for “certain rules of inference” (CR 317). He needed only two (318). He would have preferred not to use the term “dialectic” at all: “we can always use the clearer terminology of the method of trial and error” (323).

The Hegelian dialectic was futile, but Popper patiently described his understanding of it (324–331). Popper wasn’t as patient, or as “objective,” about Hegel’s “philosophy of identity.” He gave his “personal opinion” about it. “I think it represents the worst of all those absurd and incredible philosophical theories to which Descartes refers in the sentence which I have chosen as the motto for this paper” [“There is nothing so absurd or incredible that it has not been asserted by one philosopher or another” (312)] (330). Popper had found Hegel’s philosophy of identity “offered without any sort of serious argument,” and the problem it was “invented to answer—the question, ‘How can our minds grasp the world?’—seemed to Popper confusingly formulated. Popper was funny about how the idealist answer, “namely, ‘Because the world is mind-like,’” had “only the appearance of the answer” (330). He asked, Can the mirror reflect my face because it is face-like? Was Joyce’s symbol of Irish art “the cracked looking-glass of a servant” because Irish art was cracked-looking-glass-like? “Utterly unsound” way to argue, Popper said, but “formulated time and time again.”

Popper picked on James Jeans, the great popularizer of science in the 1920s and 30s, along with Arthur Eddington, but for an interesting reason. “Jeans was uneasy about the fact that our world happens to suit mathematical formulae originally invented by pure mathematicians who did not intend at all to apply their formulae to the world” (330–31). Here Popper, who may never have set out to be a popularizer of anything, followed Einstein, who looked on theories as “free creations of the human mind,” not conclusions arrived at after collecting and analyzing massive data samples. Popper didn’t find that Descartes, Kant, or Hegel began to theorize out of a sense of uneasiness, but Jeans did. Popper said that Kant “started from the fact that science exists. He wanted to explain this fact” (325). Where did Jeans’s uneasiness come from, an uneasiness that most people would feel along with Jeans, if they knew the stimulus as he did? Popper attributed the feeling to Jeans because Jeans “apparently” started off on his intellectual progress as “an ‘inductivist’; that is,”

he thought that theories are obtained from experience by some more or less simple procedure of inference. If one starts from such a position it obviously is astonishing to find that a theory which has been formulated by pure mathematicians, in a purely speculative manner, afterwards proves to be applicable to the physical world (331).

Maybe Popper himself started life as what he called an “inductivist.” Bryan Magee said several times that Popper’s greatness as a philosopher was diminished by his dogged intellectualism, his lack of interest in such crudities as psychology, human interest, etc. Here it is, though: Popper couldn’t stand men who were uneasy with the way things are. Nor was he pure in his conviction that the world was governed strictly by Newton and by chance, and that there was no perfection: if he were, how could he think that there was such a thing as a “pure mathematician” or a “purely speculative manner”? Popper, like the dialectician, would have it both ways, but his two ways weren’t their two ways: that was the difference. Or his two ways weren’t had both ways “at the same time,” as their two ways were had. Poor Jeans, to have gotten started on the wrong foot. What a good boy Karl was, to have stuck in a thumb and pulled out a plum(b):

But for those who are not inductivists, this is not astonishing at all. They know that it happens quite often that a theory put forward as a pure speculation, as a mere possibility, later proves to have its empirical applications. They know that often it is this speculative anticipation which prepares the way for the empirical theories. (In this way the problem of induction, as it is called, has a bearing on the problem of idealism with which we are concerned here.) (331)

And so Popper found himself running backwards and forwards in 1940 and getting nowhere but into the clouds and clocks of 1965, which were Peirce’s haunts in 1865. The important thing, though, was not to be at all astonished. The point was to find oneself in agreement with one of those pure mathematicians, David Hilbert, a sentence of whose Popper made the complementary motto to the third part of his 1940 talk, the synthesis, called “Dialectic After Hegel.” Hilbert’s sentence reads: “The thought that facts or events might mutually contradict each other appears to me as the very paradigm of thoughtlessness” (331). We can all understand that thoughtless thought, and the thoughtful thought that finds it thoughtless—and can do so before Hegel, after Hegel, and without Hegel. Even without Popper.

[Ari · Rating 4 out of 5]

Karl Popper is one of the leading figures in the 20th-century philosophy of science. He is primarily known for his emphasis on the concept of "falsification." The popular understanding of Popper goes something like this: Science is good, science is about falsification, and if it can't be falsified, it's nonsense. This "straw-Popperism" is open to a number of objections, advanced forcefully by e.g. Kuhn.

As it happens, Popper's thought is much more sensible and subtle than I had realized. He's perfectly aware that theories aren't simply tested on their own -- when an experiment is surprising, we typically have a choice about which of our beliefs to reject -- (including the belief that we did the experiment correctly!) His point rather is that we *ought* to set up our experiments to be as clear and unambiguous as possible so that we can make the most reliable decision about which belief to reject.

There is one point where I think Kuhn's criticism is telling. Popper implies that if we are uneasy about a theory, we should set up a decisive experiment, and if the theory is disproven, move on. As Kuhn notes, major paradigmatic theories are not generally falsified in this way. Rather, as the theory becomes increasingly problematic, scientists try to "correct" or patch the theory, and over time, if they are unsuccessful, the theory gradually disintegrates rather than being simply "rejected." This strikes me as a relatively minor point in the overall scheme of Popper's thought.

Many of the things that I found attractive in Kuhn are already in Popper. The emphasis that "scientists attack problems and puzzles," they don't go about trying to observe things at random, is Popperian. Likewise Popper already pointed out that observation is theory-dependent and that what we see depends on what we know. Poppers conclusion from this is merely "science is hard", not "objective knowledge or progress is impossible."

The book is a collection of essays and lectures, stitched together and lightly organized. This gives it a pleasing breadth of topics, at the price of some repetitiousness. Popper is generally a clear and pleasant writer, but has a tendency towards self-importance. He wants to tell you what he proved and that nobody has yet disproved it. This isn't quite my style but it's a minor point. He also blurs the distinction between descriptive and normative analysis. This is a somewhat bigger problem but I think it's easy enough to pick them apart as a reader.

[T · Rating 4 out of 5]

This is a collection of papers/lectures/essays that touches on most of the major philosophical ideas of Popper's at this stage in his career. If a person has read his previous works, this will almost seem like a review of many of his previously stated positions. But that's not necessarily a bad thing. He works hard to clarify all his ideas even more, or to present them from a new perspective, which is very much appreciated as a major help in digesting his occasionally difficult and technical thought.

There's a lot of overlap in the pieces, as Popper mentions in the introduction, so that each portion can be read as self-contained. There is, then, an element of repetition, but again, this is not necessarily a bad thing. It works to really reinforce his main points and to stress the core concepts he's presenting.

As some criticism, many words are devoted to refuting logical positivism. This is historically interesting, and Popper does use it as an opportunity to put forth his own philosophy in its place, but the critiques themselves are not so much relevant today. LP has been dead for some time, and Popper should be commended for helping to bring its death, but it's old news.

Some of his political and social philosophy towards the end seems just a bit too optimistic, as well. His comments concerning the elimination of social ills, especially regarding their existence in the United States, have not aged well.

Finally, I find his brand of mind-body dualism suspect, but there's actually little of that discussed here, so this is another minor issue.

Nevertheless, Popper is still the staunch defender of reason, rationality, science, and liberal democracy that's to be expected of him. And he's almost always on the mark more than he misses it.

[Andrew Noselli · Rating 3 out of 5]

I had some problems with this book, partly because it assumes a familiarity with many of his other works, including The Open Society and its Enemies, which I have written about on this website, The Logic of Scientific Discovery, which I had difficulty understanding and, in addition, The Poverty of Historicism, which I have yet to read. The basic summation of this book is that Popper places the logical principle of induction under erasure, in that he takes the position that inductive reasoning is poor logic in that it seeks to validate a generalized historical overview as the authorized version of the truth whereas, he argues, such a picture cannot be assumed to be a positive fact; instead, Popper continues, for induction to be true, it must include the possibility of error arising at some horizon-point in the future. In my opinion, this state of affairs is due to the essential fallibility inherent in the construction of the problem of knowledge as expounded in the symbolic universes of mathematics, linguistics and, moreover, in the fundamental definitions behind the Greek system of logic that has served as the foundation of Western epistemology for the last two thousand plus years. Three stars.

[Andrew]

Karl Popper is one of those philosophers for whom the reading is more a direct challenge to my own beliefs than an attempt to refine my current way of thinking. I should start by saying that Conjectures and Refutations is an uncommonly well-written book, and should if nothing else serve as a style guide for how to write engaging philosophy. And I should add that Popper's thesis of falsification, while it needed and continues to need refinement to give an accurate portrayal of what scientific knowledge is and how it is determined, was an absolute quantum leap in terms of epistemology and deserves praise. He starts to lose me when he gets into his philosophy, which comes off as naive and at times willfully dismissive. While he's right to criticize the flaws of orthodox Freudianism and Bolshevism-- both of which are static, dogmatic ideologies-- his system, like that of John Rawls across the Atlantic, reduces a complex situation to a sunny political centrism that, while appealingly friendly, fails to address some of the most important dynamics in the social world.

[Bill Adams · Rating 5 out of 5]

I actually read this twice... took a bit to really sink in. I was introduced to Popper by reading David Deutsch. His presentation of the scientific method in terms of conjectures and criticism is foundational to any understanding of critical thinking. One of the greatest insights of the book is that starting points aren't terribly important. You can start with the most outrageous mythology, and as long as you subject it to proper criticism, you can make progress toward eliminating error and getting closer to the truth. I would HIGHLY recommend this to anyone interested in epistemology.

[Nanto]

Review ini biang, "A hypothesis cannot be proved with a thousand supporting examples, but can be disproved by a single contrary example. Those areas that do not work like this (psychology, etc.) are not sciences but pseudo-sciences."

Ada nuansa rivalitas metodologis antara science dan non-science kah? he he he menggelitik ke-Feyerabend-an saya.

[Joe Olipo · Rating 1 out of 5]

Cogent, direct, not generous.

Perhaps in contrast with his reputation, Popper is a quick read. I believe this speaks to his legibility, which is very "Debate Club" in the sense that he will state the contention, show his proof, and conclude with a summary statement. If you know what he is trying to do, you can often fill in the second and third parts yourself (with or without the mathematical approach). Perhaps due to the thoroughness of Popper's earlier work, significant portions of Conjectures and Refutations are almost completely redundant - though he belabors the point more extensively for those who weren't able to "get it" the first time. To not run through old ruts, we will focus on the Refutations, which are responses to more concrete questions.

The crux of the Popper-ian philosophical argument is "hooking the leg," so-to-speak, meaning he is trying to demonstrate an association between an opponent's position and a (fatal) pejorative. (Very much like debate-team argumentation: "So you're a 'deontologist' let me start reading my block.") Once Popper's opponent is demonstrated to be an "inductivist" or a "positivist" or a "meta-physicist" he is subsequently refuted by the connection to a "contradiction" or a "negation" which completes the refutation. The tough part, therefore, is not the second part of the argument, which is thoroughly demonstrated, but the first step of associating an opponent's arguments with the thinking one has already demonstrated to be fallacious. Unfortunately, the Refutation requires an oppositional dialectic which frequently runs counter to Popper's previously stated principle of generosity. (In The Logic of Scientific Discovery, one is instructed only to make assumptions favorable to the opponent (such as the favorable assumptions used to construct the Carnot engine for the demonstration of the laws of thermodynamics).)

On Prediction and Refutation
If scientific theories are only valid insofar as they can be used to make predictions (per Popper) and can be disproven by an inappropriate prediction, this can (un-generously) be used as refutation of "Dialectal Materialism" on the basis of a survey of History. Yet the generous interpretation which allows us to understand western economics as a description of economic forces not necessarily refuted by predictions of certain economists and the most recent economic disaster, would also be applicable to dialectical materialism as a theory of forces of capital and labor at play in a given situation, and the analysis of these forces would be a testable outcome upon which predictions could be made, and which Popper, in good faith, cannot refute from the armchair a priori without further testing. (Popper's efforts against the Heisenberg uncertainty principle have been similarly unsuccessful.) And though it may come to pass that dialectical materialism is refuted as a theory, Popper would be "right, but for the wrong reasons," which, by his own standard, is not worth anything at all.

On Contradiction
A certain lack of generosity characterizes the description of every contradiction as a philosophical failure which "therefore permits anything." For someone so well-versed in the pre-Socratics, and author of an extensive treatise on Plato, Popper writes as if he has never encountered the aporetic dialogues, nor any of the "philosophical problems" which have characterized the history of philosophy since. The resolution of philosophical problems into soluble "contradictions" and "nonsense statements" would surely dissolve the apparent problems at hand, though they would merely saturate the transcendent analytic theory in occult form. A more generous interpretation would not stride past difficulty so easily.

On Utopia
Popper has particularly harsh words for those who, he states, wish to construct a "utopia," and therefore want to destroy society. It appears the term, "utopia," is a not-very-generous pejorative which the author is using to distance himself from a certain school of thought. The irony being that, by Popper's own metric, the testing of theories requires more and more precise measurements. The physicist constructs the particle collider to examine the properties of matter - why shouldn't the sociologist construct the sociological particle collider to test their hypothesis. The reason against this is the cryptogenic moral code which underlies the author's critique, though Popper, not (intentionally) a moral philosopher, avoids elaboration. The Revolution is refuted by two assertions: First, "The current system is pretty good," and, second, "No other system is possible." (i.e. the Revolution will eventually produce the same system we have now and will go no further.) Popper may or may not be correct, but it has been demonstrated (by experiment) that his axiomatic faith has produced some risible blunders. From Popper's A History of Our Time (1956):

"[Regarding the United States, Canada, England, and New Zealand] we have, in fact, something approaching classless societies."

"Aggressive war has become almost a moral impossibility. [...] Thus as far as the free world is concerned, war has been conquered."

"The truth is that the idea of India’s freedom was born in Great Britain; [...] And those Britishers who provided Lenin and Mr Krushchev with their moral ammunition were closely connected, or even identical, with those Britishers who gave India the idea of freedom."

To what extent is Popper's academic ascent due to graduate students for whom the opportunity to grade ten lines of "philosophical arithmetic" rather than ten pages on Hegel is already Utopia?