Friday, July 20, 2007

The Logic of Scientific Discovery (Karl Popper)

Tansu KUCUKONCU , PhD
( Tansu KÜÇÜKÖNCÜ ( in Turkish alphabet ) )
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The Logic of Scientific Discovery ( Karl Popper , 1959 )

( Logik der Forschung , 1934 )

Book review and criticism by Tansu KUCUKONCU

Popper believes that philosophy is a must activity; because we all aasumes lots of things things as data, and most of these assumptions are philosophical.

Popper is undeterminist both in physics and in politics. He claims that it is logically improbable to predict the flow of history in the future.

It is argued for a long time that the basic duty of science is to search for the natural laws.

First systematic works in this subject have been performed by Francis Bacon.

Scientist, at a point on the border of our knowledge and unknowledge, begins with experiments which aims to make carefully controlled and measured observations. He edits his findings. With these editions and time, that scientist and the others working on the same area cumulates lots of knowledge which are shared and trusted. General charecteristics begins to appear with growing of these cumulative knowledge. Then individuals begins to claim general presuppositions (these are law-like propositons which fit all known events and explain the causal relations between them. A scientist tries to justify his proposition by finding evidences which will support them. If his justification becomes succesful, this means that he found a new scientific law which will explain much more secrets of nature. Then, this investigation is applied to everywhere in where it is assumed that it can generate new knowledge. Thus, new ones are added to existent scientific knowledge set, hence border of our knowledgelessness is pushed back.

This method of lasting general propositions to cumulative observations of original cases is called as 'induction', and this is the distinguishing property of science. Usage of induction method is assumed the demarcation between science and non-science.

Growing of science happens in duration of adding new realities tothe existent ones. Hume: pointed out that singular observations, whatever their amount is, logically, could not reach unconditional general propositions.

Understanding of currency of physical laws in the past does not mean, logically, that they will be current in the future.

All of our science assumes the regularity of nature (it is assumed that in the view of all cases where natural laws works, future will be just like the past), but there is no way to justify this proposition. It can not be proved by observation, because future events cannot be observed. It cannot be proved logically, too, because the result that 'all futures in future will seem like pasts in future' cannot be derived from the cause 'all futures in the past seemed like pasts in the past'.

There is no way to prove the currency of inductive durations. But our psylogical structure is organized such that we cannot think without them. Russel: Hume showed that pure experimentalism is not a sufficient ground for science. Hume: Induction is a logical basic which is independent of experiment and other logical basics, and science is impossible without this basic....

It must be accepted that scientific laws cannot be justified, therefore they are not certain. In spite of this every justifyable sample increases their degree of probability; addition to all the past known, every instance of the continuity of the world provides billions of justifyable samples, but don't bring any counter-sample. Therefore, even though they are not certain, they are probable at the highest thinkable level, and maybe not in theory, but in practice it is not possible to distinguish them from certainty. Popper: He points out the asymmetry between justification and falsification.

Experimental generalizations cannot be justified, but can be falsified. This means that eventhough scientific laws are justifyable, but they are testable.

In logic, a scientific law cannot certainly be justified, but theycan certainly be falsified. In methodology, it always is possible tosuspect from any propopsition. Therefore, for us, without falling into any contradiction with ourselves, it always is possible to reject the currency of any experimental proposition. Hence, we can reject all falsificative experiments.

He proposes as a methodological basic that, we should avoid from denying (using ad hoc assumptions or definitions or another systematic way) the currency of experimental results which seem unconvinient for us; according to this, for making our theories be open for falsification, we should formulate them far from multi-meaningness. At the same time, he advises that we should not abondon our theories, because then this will be a situation which is far from criticism against tests.

In these conditions, in logic, he can be called as a naive falsificatist, but in methodology, he is a very critical falsificatist.

Whether our theory is true, nor it is false it says more things about world than we know until that time.

If some of the things which our theory says, this becomes a new investigation: it increases our knowledge and makes our search for better theory re-start.

Improvement of our knowledge occurs by our meeting with new problems and trying to solve them.

Nothing in science is continuously justified and permanent, and it is clear that science continuously is changing, but this occurs by addition of new certainties to science.

We last our decisions and expectations to 'what and ho much we know', and we temporarily assume the truthness of that knowledge for practical purposes; because it is the laest untrustable basic; but we don't forget that, at any time, experiment might show its falseness and we will have to change it.

All measurements of both space and time can be certain only at some level.

Our purpose in searching knowledge is to approach to true more and more, even we can know that we are going forward in this way, but we certainly cannot know whether we reach our target or not. We cannot accept science as synonym with true; because we accept theories of both Newton and Einstein as science; both cannot be true, moreover both can be false.

The work of understanding the world has no rules.

He says that the induction method is an abondonable concept. It is a myth. There is nothing which is called as induction. Any different thought, which is more true, can be substituted its place.

How a theory is reached has no scientific and logical meaning. Therefore no way is illegal. This is not a logical, but a psylogical duration.

All the problem of induction is because that we cannot distinguish between logical and psylogical durations.

A logic of 'creativeness' in science is as impossible as that in art. Einstein: Supports the ideas of Popper.

There is no logical way to investigate laws of the natura.

Theory can not be made of observational results, but be investigated. Popper: Observation cannot directly be before theory, because there must exist a bit of theory in each observation.

It is meaningless the belief that, without anything, we can begin with pure observation.

Observation is always selective. It requires a selected object, a certain work, an interest, a point of view, a question. Description of it requires the existence of a language which has descriptive property words, the existence of similarities and grouping; these themselves requires again interest, point of views and problems. This means that observations, especially the propositions of observations and experiments, always are the interpretations of observed concepts; these are interpretations in the light of theories.

Our knowledge can only be exist by means of our theories.

Concepts of our thinking are not given by objective regularities, but thay are (created and) improved in response to our problems, interests and point of views.

Understanding of concepts ('what' questions about them) takes us to meaningless loops and verbalism. Moreover, this explanation process may cause the creation of new concepts which even must be explained. Therefore we should not try to lighten the concepts before testing theories.

If how much a proposition gives knowledge, the ways in which its falseness can be shown increases that much.

What we want is the propositions whose knowledge content is high, hence its probability is law, but reaches to truth more. Being falsifyable in a high degree makes them testable at a high degree, too. Popper: Our knowledgelessness increases with our knowledge, so we always will have more questions than our answers.

A theory should bring an answer to our problems. At the same time it should be in accordance with all known observations, and contain the theories before it as approximate solutions; in addition to this it must explain the reasons of their unsuccessfullness.

At a certain time, the theory between the competing theories whichgives the best results is the one which is supported with its contentwhich can give knowledge at the highest level; therefore it should be the sovereign one.

For lots of purposes, a proposition which is a bit false is more usefull than a true, but undetermined one.

We should formulate our theories as certain as possible.

The distinguishing factor between science and non-science is 'falsifyableness'.

Historically, foundations of all the theories can be found in myths, and a myth can contain some elements which informs scientific theories. Therefore if it is understood that a theory is unscientific or metaphysical, just because of this it cannot be said that it is meaningless or nonsensical.

These ideas are just the opposites those of logical positivists.

An idea which is accepted as metaphysical (because it is not testable) at a time, later may be testable by changing of the conditions, therefore becomes scientific.

A metaphysical theory even can be true.

Language is an instrument, and what is important is what is done with it (not the way in which the words are used).

The main problem of philosophy (maybe the question in which all humen are intersted in): understanding of the world (ourselves and our knowledge as an element of it).


Evolutionism

Popper: Theory of innate ideas is meaningless. But each organism has innate reactions and responses. Thses can be called as 'expectations' (unconscious).

Because of the close relations between knowledge and interset, in a rational level, we can talk about 'innate knowledge'. But this knowledge is not effective as a priori.

We birth with expectations, these are not a priori philosophically, but psycologically and genetically, and these are knowledges that comes before every kind of observational experiment.

Elimination of falses occur in a natural-selection way.

Language made improvement of mind (reflection) be possible. It is the basic element of consciousness.

Religion, myth, useless beliefs, language, these are human-made. But these are created without planning. Maybe there were no need for them until they created.

World1: A world of material things which are objective.

World2: A world of ideas which is subjective.

World3: A world of material things which are created by minds or living things (they exists free from their creators after creation), which are objective.

We are social creatures. Nobody is free of the past (history)effects of other people.

We progress by criticising conventions and by making changes on it.

We don't know where and how to begin to understand tha world. Even science and convention cannot say this to us . They can only say whereand how the others begin.

If a theory is scientific, and it is carefully tested by its proposer, scientific world does not accept this before its experiments and observations are repaeted by other people.

Knowledge are not in the special mind situations of individuals, but it is in social area.

From the special individual point of view, most of human knowledge does not be known by anybody. It is only on paper.

Nobody can repeat (word by word) his own writings (i.e. a writer of a book).

What we know is that we can know.

Knowledge is free of its knower.

In objective meaning, knowledge is knowledge which has no knower, which has no knowing subject.

Scientific knowledge is not the knowledge in the ordinary usage ofthe sentence 'I know'.