Lecture 1: What is philosophy of science?
What is pseudoscience?
Theoretical importance = a sharp dividing line between science and pseudoscience would
give us insight into what science is, analogous to what the study of fallacies contributes to
our understanding of good arguments.
Practical importance = in many areas science is our most reliable source of knowledge. We
must be able to distinguish sciences from its lookalikes Like medicine, law, education and
environmental politics.
What do we mean by science?
With science we mean the exact sciences and related disciplines (cognitive psychology,
political economics).
Wissenschaft are all academic disciplines, including the humanities.
The exact sciences, social science and the humanities are interrelated and interdependent
parts of the same great enterprise; to understand man, nature and society.
Pseudoscience?
Science broadly conceived is more useful is we want to understand what pseudoscience is:
the abuses of history by Holocaust-denialists are methodically similar to the abuses of
natural science by creationists and (classical) homeopaths.
Note: these are methodical similarities, no similarities in context.
What is pseudoscience?
Unscientific is more specific than non-scientific because it implies a conflict with scientific.
Pseudoscientific is more specific than unscientific because not all bad science is
pseudoscience.
Pseudoscience = ‘A pretended or spurious science; a collection of related beliefs about the
world mistakenly regarded as being based on scientific method or as having the status
scientific truths now have.
A first attempt at a definition → a given discipline is pseudoscientific if it meets
the following two conditions:
- it is not scientific
- its proponents strongly suggest that it is scientific.
The problem with this definition is that it is far too broad. There are disciplines that meet
these two conditions, although we would not be prepared to call them pseudoscientific. Think
of (very) bad science, such as scientific fraud.
Pseudoscience also includes adherence to some deviant doctrine. It is a sustained effort to
endorse doctrines that deviate from accepted scientific doctrines.
A second attempt at a definition → An activity or doctrine is pseudoscientific if it
meets the following three conditions:
- It is not scientific
- It is part of a non-scientific discipline
- Its proponent strongly suggest that the discipline is scientific.
,This definition is not satisfactory either, because some clear cases of pseudosciences are
not ruled out by this definition.
Pseudoscientists often claim to offer alternatives for accepted scientific doctrine or to offer
explanations for phenomena that cannot be ‘handled’ by accepted scientific doctrine.
A third attempt at a definition → an activity or doctrine is pseudoscientific if it
meets the following two conditions:
- It is not scientific
- It is part of a non-scientific disciple that conflicts with (good) science.
It is hard to distinguish pseudoscience from anti-science. Proponent of some
pseudosciences vacillate between (1) opposition against accepted science, and (2) the claim
that they themselves advocate the best science can offer.
Alternate criteria 1.
Logical positivist: A sentence is cognitively meaningful if it logically entails at least one
observation sentence:
- The absolute is perfect.
- But: we will see that their criterion of cognitive meaningfulness was aimed against
metaphysics, and not against pseudoscience.
- Moreover, many pseudoscientific claims are cognitively meaningful.
We therefore cannot use the criterion of cognitive meaningfulness for a definition of
pseudoscience.
Alternate criteria 2.
Karl Popper: statements or systems of statements, in order to be ranked as scientific must
be capable of conflicting with possible, or conceivable observations.
- Popper’s definition has the untoward consequence of countenancing as scientific
every crank claim which makes ascertainable false assertions.
- Nonetheless, popper keeps on endorsing this definition.
- The early Popper also claimed that the theory of natural selection cannot be falsified
(Later on, he revised his view on evolution).
Alternate criteria 3.
Thomas Kuhn: Popper’s definition only makes sense in case of so-called scientific
revolution. A definition of pseudoscience should aim at normal science. The power to solve
puzzles si a characteristic of real science.
- Since antiquity, astronomy solves all kinds of puzzles and hence is scientific. If some
astronomical prediction does not come out true, we have a puzzle that must be
solved by more measurements or by revising our theory.
- In astrology there is not puzzle-solving: ‘particular failures did not give rise to
research puzzles, for no man however skilled, could make use of them in a
constructive attempt to revise the astrological tradition.
Alternate criteria 4.
Paul thagard: We need an addition criterion, because science does not take place in a
vacuum but within a social context.
An addition condition for pseudoscience is that the community of practitioners makes little
attempt to develop the theory towards solutions of problems, show no concern for attempt to
,evaluate the theory in relation to others, and is selective in considering confirmations and
disconfirmations.
Alternate criteria 5.
Sven Ove Hansson gives seven criteria for pseudoscience:
1. An authority cult
2. Unrepeatable experiments
3. Hand-picked examples
4. Unwillingness to put theories to test
5. Disregard for counter-evidence
6. Built-in immunization strategies
7. Explanations are rejected even if there are no plausible alternative explanations.
Pseudoscience.
There is no commonly accepted definition of pseudoscience. Nonetheless, there is a broad
consensus about great meany examples of pseudoscience: creationism, ufology, astrology,
classical homeopathy, AIDS-denialism, Holocaust-denialism, climate change scepticism etc,
etc.
We need to defend science against the crackpots.
Philosophy of science
How to understand the interplay between science and society (externalistic):
- Is science a factor in our moral beliefs?
- Do our moral beliefs affect science?
- How to understand the interplay between science and society?
- Is science a threat to our society?
- Is our society threatening science?
What is science (interralistic)
- What makes science and science-based technology reliable?
- What methods guarantee this reliability?
- Can we use these methods to defend a principled distinction between science and
pseudoscience?
Lecture 2: Logical empiricism + confirmation.
Logical empiricism
Why does scientific research give us reliable knowledge?
- To answer this question, we need to study the scientific method (e.g. theory choice,
deduction, induction, confirmation), but also scientific explanations.
What conditions should a scientific explanation meet?
- We need a normative answer here, because we want more than just a summary of
what scientists do.
- We hence need a philosophical assessment of the explanations that have been
adduced by scientists.
- Explanations depend on the relation between theory and observation.
How should we understand the relation between theory and observation?
, Empiricism = our (scientific) knowledge can only be justified by experience
- Scientific truths are contingent, not necessary
- Our knowledge cannot transcend experience
The logical positivists developed a philosophy of science that combined modern logic with
an empirical stance.
They applied this new theory of science to physics and to psychology.
The logical positivist observed that the scientific revolution of the 17th century was made
possible by using mathematics to interpret observations and outcomes of experiments.
Accordingly there are two types of sentences:
- Analytic statements: do not depend on the world.
- Contingent statements: depend on the way the world is.
Why are analytic statements (i.e. logical and mathematical statements), according to the
logical positivists, necessary true?
Analytic statements.
Analytic statements are either definitions or provable from these definitions by way of
deductive reasoning.
- Definitions do not have a truth-value (i.e. they are not true or false), but are simply
more or less suitable for a specific application.
- Definitions are conventions: they just tell us how we are going to use certain
symbols, but do not tell us anything about the functioning of the world.
- ‘’2+2=4’’ is a necessary truth, because once we have laid down the conventions that
rule the uses of ‘’2’’, ‘’+’’ and ‘’=”” , it cannot be otherwise.
- ‘’A bachelor is an unmarried man’’ is a necessary truth, because ..
Contingent statements.
The logical positivists advocated a criterion of cognitive meaningfulness to define the class
of contingent statements, statements that are true or false depending on the way the world
is. In this way, they wanted to do away with meaningless knowledge claims (theology,
metaphysics, etc)
A statement is only cognitively meaningful if and only if its truth can only be assessed by way
of experiences.
It turned out to be very hard to come up with a criterion of cognitive meaningfulness that
perfectly defines the class of contingent statements.
Confirmation.
How are we to understand the relation between theory and observation?
We make a couple of idealizing assumptions:
- A theory is some sort of universal statements, a statement of the form ‘’All X’s are
Y’s’’.
- Observations are statements about particulars and hence of the form ‘’a is an X’’, ‘’a
is not an X.
In some cases a universal statement logically implies statements about particulars. We use
the notion of deductive validity to make this precise.
Deductive reasoning.
What is pseudoscience?
Theoretical importance = a sharp dividing line between science and pseudoscience would
give us insight into what science is, analogous to what the study of fallacies contributes to
our understanding of good arguments.
Practical importance = in many areas science is our most reliable source of knowledge. We
must be able to distinguish sciences from its lookalikes Like medicine, law, education and
environmental politics.
What do we mean by science?
With science we mean the exact sciences and related disciplines (cognitive psychology,
political economics).
Wissenschaft are all academic disciplines, including the humanities.
The exact sciences, social science and the humanities are interrelated and interdependent
parts of the same great enterprise; to understand man, nature and society.
Pseudoscience?
Science broadly conceived is more useful is we want to understand what pseudoscience is:
the abuses of history by Holocaust-denialists are methodically similar to the abuses of
natural science by creationists and (classical) homeopaths.
Note: these are methodical similarities, no similarities in context.
What is pseudoscience?
Unscientific is more specific than non-scientific because it implies a conflict with scientific.
Pseudoscientific is more specific than unscientific because not all bad science is
pseudoscience.
Pseudoscience = ‘A pretended or spurious science; a collection of related beliefs about the
world mistakenly regarded as being based on scientific method or as having the status
scientific truths now have.
A first attempt at a definition → a given discipline is pseudoscientific if it meets
the following two conditions:
- it is not scientific
- its proponents strongly suggest that it is scientific.
The problem with this definition is that it is far too broad. There are disciplines that meet
these two conditions, although we would not be prepared to call them pseudoscientific. Think
of (very) bad science, such as scientific fraud.
Pseudoscience also includes adherence to some deviant doctrine. It is a sustained effort to
endorse doctrines that deviate from accepted scientific doctrines.
A second attempt at a definition → An activity or doctrine is pseudoscientific if it
meets the following three conditions:
- It is not scientific
- It is part of a non-scientific discipline
- Its proponent strongly suggest that the discipline is scientific.
,This definition is not satisfactory either, because some clear cases of pseudosciences are
not ruled out by this definition.
Pseudoscientists often claim to offer alternatives for accepted scientific doctrine or to offer
explanations for phenomena that cannot be ‘handled’ by accepted scientific doctrine.
A third attempt at a definition → an activity or doctrine is pseudoscientific if it
meets the following two conditions:
- It is not scientific
- It is part of a non-scientific disciple that conflicts with (good) science.
It is hard to distinguish pseudoscience from anti-science. Proponent of some
pseudosciences vacillate between (1) opposition against accepted science, and (2) the claim
that they themselves advocate the best science can offer.
Alternate criteria 1.
Logical positivist: A sentence is cognitively meaningful if it logically entails at least one
observation sentence:
- The absolute is perfect.
- But: we will see that their criterion of cognitive meaningfulness was aimed against
metaphysics, and not against pseudoscience.
- Moreover, many pseudoscientific claims are cognitively meaningful.
We therefore cannot use the criterion of cognitive meaningfulness for a definition of
pseudoscience.
Alternate criteria 2.
Karl Popper: statements or systems of statements, in order to be ranked as scientific must
be capable of conflicting with possible, or conceivable observations.
- Popper’s definition has the untoward consequence of countenancing as scientific
every crank claim which makes ascertainable false assertions.
- Nonetheless, popper keeps on endorsing this definition.
- The early Popper also claimed that the theory of natural selection cannot be falsified
(Later on, he revised his view on evolution).
Alternate criteria 3.
Thomas Kuhn: Popper’s definition only makes sense in case of so-called scientific
revolution. A definition of pseudoscience should aim at normal science. The power to solve
puzzles si a characteristic of real science.
- Since antiquity, astronomy solves all kinds of puzzles and hence is scientific. If some
astronomical prediction does not come out true, we have a puzzle that must be
solved by more measurements or by revising our theory.
- In astrology there is not puzzle-solving: ‘particular failures did not give rise to
research puzzles, for no man however skilled, could make use of them in a
constructive attempt to revise the astrological tradition.
Alternate criteria 4.
Paul thagard: We need an addition criterion, because science does not take place in a
vacuum but within a social context.
An addition condition for pseudoscience is that the community of practitioners makes little
attempt to develop the theory towards solutions of problems, show no concern for attempt to
,evaluate the theory in relation to others, and is selective in considering confirmations and
disconfirmations.
Alternate criteria 5.
Sven Ove Hansson gives seven criteria for pseudoscience:
1. An authority cult
2. Unrepeatable experiments
3. Hand-picked examples
4. Unwillingness to put theories to test
5. Disregard for counter-evidence
6. Built-in immunization strategies
7. Explanations are rejected even if there are no plausible alternative explanations.
Pseudoscience.
There is no commonly accepted definition of pseudoscience. Nonetheless, there is a broad
consensus about great meany examples of pseudoscience: creationism, ufology, astrology,
classical homeopathy, AIDS-denialism, Holocaust-denialism, climate change scepticism etc,
etc.
We need to defend science against the crackpots.
Philosophy of science
How to understand the interplay between science and society (externalistic):
- Is science a factor in our moral beliefs?
- Do our moral beliefs affect science?
- How to understand the interplay between science and society?
- Is science a threat to our society?
- Is our society threatening science?
What is science (interralistic)
- What makes science and science-based technology reliable?
- What methods guarantee this reliability?
- Can we use these methods to defend a principled distinction between science and
pseudoscience?
Lecture 2: Logical empiricism + confirmation.
Logical empiricism
Why does scientific research give us reliable knowledge?
- To answer this question, we need to study the scientific method (e.g. theory choice,
deduction, induction, confirmation), but also scientific explanations.
What conditions should a scientific explanation meet?
- We need a normative answer here, because we want more than just a summary of
what scientists do.
- We hence need a philosophical assessment of the explanations that have been
adduced by scientists.
- Explanations depend on the relation between theory and observation.
How should we understand the relation between theory and observation?
, Empiricism = our (scientific) knowledge can only be justified by experience
- Scientific truths are contingent, not necessary
- Our knowledge cannot transcend experience
The logical positivists developed a philosophy of science that combined modern logic with
an empirical stance.
They applied this new theory of science to physics and to psychology.
The logical positivist observed that the scientific revolution of the 17th century was made
possible by using mathematics to interpret observations and outcomes of experiments.
Accordingly there are two types of sentences:
- Analytic statements: do not depend on the world.
- Contingent statements: depend on the way the world is.
Why are analytic statements (i.e. logical and mathematical statements), according to the
logical positivists, necessary true?
Analytic statements.
Analytic statements are either definitions or provable from these definitions by way of
deductive reasoning.
- Definitions do not have a truth-value (i.e. they are not true or false), but are simply
more or less suitable for a specific application.
- Definitions are conventions: they just tell us how we are going to use certain
symbols, but do not tell us anything about the functioning of the world.
- ‘’2+2=4’’ is a necessary truth, because once we have laid down the conventions that
rule the uses of ‘’2’’, ‘’+’’ and ‘’=”” , it cannot be otherwise.
- ‘’A bachelor is an unmarried man’’ is a necessary truth, because ..
Contingent statements.
The logical positivists advocated a criterion of cognitive meaningfulness to define the class
of contingent statements, statements that are true or false depending on the way the world
is. In this way, they wanted to do away with meaningless knowledge claims (theology,
metaphysics, etc)
A statement is only cognitively meaningful if and only if its truth can only be assessed by way
of experiences.
It turned out to be very hard to come up with a criterion of cognitive meaningfulness that
perfectly defines the class of contingent statements.
Confirmation.
How are we to understand the relation between theory and observation?
We make a couple of idealizing assumptions:
- A theory is some sort of universal statements, a statement of the form ‘’All X’s are
Y’s’’.
- Observations are statements about particulars and hence of the form ‘’a is an X’’, ‘’a
is not an X.
In some cases a universal statement logically implies statements about particulars. We use
the notion of deductive validity to make this precise.
Deductive reasoning.
