Lecture 9: Logical positivism & theory-ladenness Flashcards
waar en wanneer was Wittgenstein geboren
Vienna, before WWI
welke twee werken van wittgenstein
- Wittgenstein I: Tractatus Logico-Philosophicus
- Wittgenstein II: Philosophical investigations
wanneer wittgenstein 1
1921
wanneer wittgenstein 2
1953
Together these ‘two’ Wittgensteins form the
most influential philosopher of the 20th century
oke
wat was wittgenstein voor gast
mega rijk, influentiele ouders, had veel connecties met bv Freud en Klimt, zat op school met Hitler (kreeg eigen geschreven brief dat hij als jood niet mocht worden opgepakt)
wat was zo bijzonder aan de boeken
they had 2 opposing views, but both about the philosophy of language
wat wilde wittgenstein eigenlijk
een soort formal strict language, that could be used to form all kinds of knowledge about logic
russels paradox =
if R contains itself, then R must be a set that is not a member of itself by the definition of R, which is contradictory; if R does not contain itself, then R is one of the sets that is not a member of itself, and is thus contained in R by definition–also a contradiction.
gaat er dus over dat een set van dingen (bv een bloemenverzameling: bestaat uit rozenverzameling, hyacintenverzameling etc) niet zelf ook een member van die grotere verzameling mag zijn
paradox=
when something is true and untrue at the same time
wat haalde wittgenstein uit russels paradox
the paradox stems from a lack of clarity in what it is that makes something ‘meaningful’
waar ging het eerste werk van wittgenstein over
‘what is a meaningful sentence’
waar werd Tractatus geschreven
trenches of WO1, he finished in a camp in Italy
wittgenstein wist niet dat zijn boek gepubliceerd zou worden
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wat is het belangrijkste zinnetje van de tractatus logico-philosophicus
die welt is alles, was der fall is (the world is everything that is the case)
wat waren de conclusies van de tractatus logico-philosophicus
- the world is the totality of facts
- logical atomism
- complex facts are a combination of elementary facts
- all facts together constitute the world (all that is the case)
- a thought or statement expresses a possible state of affairs in this world
- if the state of affairs, depicted by the thought, does occur, then the thought is true
- if the state of affairs does not occur then the thought is not true but it is meaningfull
a fact volgens wittgenstein =
a fact is an existing state of affairs
logical atomism=
elementary facts are indivisible and independent of each other
complex facts are a combination of elementary facts. elementary facts =
constituents
picture theory of truth=
when a state of affairs depicted by the thought does occur, then the thought is true and meaningful
state of affairs =
things that are possible, represents the meaning of the thought
the meaningfullness of a thought depends on….
the truth of a thought depends on..
the state of affairs (is it possible?)
whether it comes true or not
A thought or statement expresses …
a possible state of affairs in this world
a statement needs to have … for it to be true
conditions
dus een voorbeeld van truth versus state of affairs
truth: there is a chair in the library
state of affairs: there is an elephant in the library (het kan zo zijn, maar is niet zo)
the world only exists from…
facts!!!
(=existing state of affairs)
dus als iets wel mogelijk is, maar niet zo is in dit geval…
meaningful but false
f the state of affairs does not occur…
then the statement is not true but it is still meaningful
meaningful statements depict…
possible states of affairs
statements that dont depict a possible state of affairs…
are meaningless
wat is een conclusie van al deze dingen voor language
language cannot express anything ‘higher’: it cannot represent ethics or aesthetics, because they withdraw themselves from the sayable. want het zijn vaak geen mogelijke state of affairs, het zijn geen duidelijke statements: je kan nooit met 100% zekerheid zeggen of iets beautiful of good is (want mensen hebben andere meningen etc). dus daarom zijn deze statements meaningless.
‘the sayable’
meaningful statements
This is one of the most influential thoughts of the 20th century,what does it imply
Statements that don’t depict a possible state of affairs are meaningless: As a result, language cannot express anything “higher”; ethics and aesthetics, for example, withdraw itself from the sayable
the limit of the sayable
- 6.52: “We feel that even when all possible scientific questions have been answered, the
problems of life remain completely untouched” - 6.522: “There are, indeed, things that cannot be put into words. They show themselves. They are what is mystical”
- 7: “Whereof one cannot speak, thereof one must be silent
wat werd bedoeld met de ‘mystical turn’ aan het einde van de tractatus
- scholars disagree about this:
- one interpretation = we can show some things that we cannot say (love: geen factual state of affairs, but we can show it)
“On the other hand the truth of the
thoughts that are here
communicated seems to me
unassailable and definitive. I
therefore believe myself to have
found, on all essential points, the
final soluton of the problems. And
if I am not mistaken in this belief,
then the second thing in which the
value of this work consists is that it
shows how little is achieved when
these problems are solved.” -
Vienna, 1918
wittgenstein quits philosophy
wat gebeurde er in 1920
- Wiener Kreis (vienna circle) van scientists, mathematicians and philosophers
- wanted to base philosophy on science and logic
- enorme invloed door wittgensteins tractatus
- plotting attack on traditional vague philosophy (metaphysics)
voorbeeld van een logical positivist
alfred ayer
If someone asserts “there is a
God”, “the primary basis of the
world is the unconsciousness”,
[…], we do not say to him:
“what you say is false”; but we
ask him: “what do you mean
by these statements.” […]
[These statements] reveal
themselves as empty of
meaning if one takes them in
the way that metaphysicians
intend
otto neurath, logical positivist
dus wanneer kwam logical positivism ongeveer op
1920
the linguistic turn:
- the mind has been drawn into the domain of the natural sciences, therefore where does philosophy belong?
- wanted to give philosophy a new purpose: the clarification of language, which sentences are meaningful?
- revolution in philospophy
- “philosophical questions are the questions of language”
“I shall mean by ‘linguistic philosophy’
the view that philosophical problems
are problems which may be solved (or
dissolved) either by reforming
language, or by understanding more
about the language we presently use.”
–Richard Rorty
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wat vonden zij over de natural sciences en language?
That which remains after the language has been clarified and stripped of meaningless claims, becomes the subject of natural science.
wat was de manifesto van logical positivism
- “The scientific conception of the world: the Vienna Circle”
- This manifesto starts philosophy of science as a separate philosophical discipline
- It deeply marks thinking about science – especially in psychology
- One of the most influential pieces in history
4 starting points of the logical positivists
- meaningful claims are either empirical or logical in nature
- logical claims are verifiable by looking at their form (logic & mathematics bv) and help represent the world
- empirical claims are about the world and can be verified by observation
- claims that are not verifiable are meaningless
the verifiability criterion =
only sentences that are verifiable are meaningful
hoe hadden ze dit criterion bedacht
door een aanpassing van wittgenstein 1: die zei namelijk ‘meaningful statements express a possible state of affairs’
voorbeelden van meaningfull en meaningless statements
- Some meaningless sentences:
– Donald has an Oedipus complex
– The soul is immortal - Some meaningful sentences:
– There are now 356 people in this room
– The scale indicates 34 kg
op wie leken de logical positivists
British empiricist David Hume
3 overeenkomsten logical positivists & Hume
- Hume is empiricist
- And his rejection of the notion of causality was based on similar considerations
- Crusade against nonsense
even kijken naar blaadje met schema van meaningful claims
oke
wat was er toen wittgenstein eindelijk naar de vienna circle kwam
hij leek meer op een creatieve artiest, religious en zonder rationele comments etc. dus dit viel tegen
wat zeiden logical positivists over experiences
experiences are gained via sensory perception.
wat was een assumption over deze experiences
experiences are neutral, so that they can serve as a foundation for science.
= sense data
verification is ….
the comparison of descriptions of observations with these sense data
theoretical statements are verified through …
observation sentences (= descriptions of observations)
Sense data are…
factual descriptions of perception, like seeing a stick in the water
wat is de structure of science
sense data
verification
observational vocabulary
correspondence rules
theoretical vocabulary
regularities
law
rorty zei
problems can be solved by reconstructing and understanding language (= linguistic philosophy)
cross race effect
people are better at recognizing faces of people of the same race
problems with verifiability
1: separation of theory and observation
2: underdetermination of theory by data
3: induction
4: unobservable entities
hoe kom je volgens logical positivists van observation naar theory
- the logical positivists make a strict separation between observation and theory
- statements directly describing reality are called observation sentences, which are linked to theoretical vocabulary
- through these correspondence rules, the content of theoretical concepts is reduced to observation.
problem: separation of theory and observation
- theoretical concepts cannot be reduced to observations
- theory ladenness
wie realiseerde als eerste dat open concepts cannot be reduced to observations
arthur pap
theories cannot be reduced to observations =
theoretical terms are much richer, they therefore cannot just be reduced to observations (especially open concepts)
theoretical statements are much richer!
je kan bijvoorbeeld niet ‘vain’ of ‘IQ’ zien via observations alleen. vooral open concepts in psychologie
theory ladenness=
- logical positivists assumed that observations are neutral
- but they are not!
- very different: observing X, or observing that X has property Y
- the latter observation relies on a theory that defines property Y
- scientific observations are often based on instruments: and their accuracy itself is based on theory
dus observations are theory-laden
voorbeeld theory-ladenness van fmri scan uitslagen
The interpretation of this fmri image rests on theory about how the scanner works
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underdetermination of theory by data =
vaak is het zo dat we verschillende mogelijke modellen hebben: in de praktijk gebruiken we theorie om een model voor iets te kiezen: dit zou volgens de logical positivists niet mogen.
theories are sometimes equivalent in their empirical consequences. so, to choose between theories, scientists then use other criteria (elegance, efficiency) -> but those criteria themselves are theoretical!
= underdetermination of theories by empirical data.
Some network models and latent variable
models are equivalent, yet representing
very different theories
oke
induction problem =
- general statements are not verifiable
- specifically statements about infinite sets
- dus general laws are not verifiable (en dus klopt die hele theorie niet)
- so with the verification criterion, causal relationships cant be part of science
David Hume once again makes things difficult…
lol
unobservable entities=
- in the 20th century, science filles with unobservable entities (atoms, photons etc)
- statements about unobservable entities are not verifiable and also not reducible to observations
- plus, new techniques make new entities observable
- but were statements about microbes meaningless untill the invention of the microscope??? no!!
- therefore, if we would have followed the verification criterion we would not have known a lot of different things
wittgenstein returns….
- After years in self-chosen isolation Wittgenstein returns to Cambridge
- He starts a complete new theory of meaning
- Meaning arises in language games
- Completely opposing the “received view” of the logical positivists
wat gebeurde er na de fall van logical positivism (wat voor dingen werden nu gerealiseerd)
- There are no sense data
- Everything is subject to interpretation
- Theoretical terms are not reducable to observations
- There are always multiple possible interpretations
- And you run into the good old induction problem
- With Wittgenstein in hand, the logical positivists open up a new area of philosophy: the philosophy of science.
- They try to demarcate meaningful statements based on the verification criterion: statements that cannot be verified are meaningless. Science should only consider verifiable statements
oke
Verification criterion does not work because
– Theory and observation cannot be strictly separated (open concepts, theory-ladenness)
– Underdetermination of theory by observation
– statements about infinite sets, causality, and unobservable entities are not verifiable but clearly meaningful
– Science is full of unobservables and they can become observable
oke
- The verification criterion thus describes half of science as meaningless chitchat
- Are the rationalists better in providing a good analysis of science?
oke
