1 st Term 2016 Science amp Philosophy Popes Epitaph N ATURE and Natures Laws lay hid in Night God said Let Newton be and all was light Isaac Newton Completed the scientific revolution with his Principia where he specifies the laws of physics ID: 781085
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Slide1
Verificationism
PHIL 2610 Philosophy of Language
1
st
Term 2016
Slide2Science & Philosophy
Slide3Pope’s Epitaph
N
ATURE
and Nature’s Laws lay hid in Night:
God said, “Let Newton be!” and all was light.
Slide4Isaac Newton
“Completed” the scientific revolution with his Principia, where he specifies the laws of physics.
Also known for his development of the integral calculus and his work in optics.
Friend of Locke.
Slide5Robert Boyle
Founder of modern chemistry.
Pioneer of experimental scientific methodology.
Known for “Boyle’s Law”
Locke worked in his lab.
Slide6Slide7Locke on His Essay
“The commonwealth of learning is not at this time without master-builders, whose mighty designs, in advancing the sciences, will leave lasting monuments to the admiration of posterity: but every one must not hope to be a Boyle or a Sydenham;
and in an age that produces such masters as the great
Huygenius
and the incomparable Mr. Newton, with some others of that strain, it is ambition enough to be employed as an under-
labourer
in clearing the ground a little, and removing some of the rubbish that lies in the way to knowledge;”
Slide8Locke on His Essay
“This, therefore, being my purpose — to inquire into the original, certainty, and extent of human knowledge, together with the grounds and degrees of belief, opinion, and assent;”
Slide9Albert Einstein
Developed the Theory of Relativity, which would replace Newton’s Laws of Motion.
Also ver
y influential in the development of Quantum Mechanics.
Slide10The Curvature of Spacetime
Kant influentially held that Euclidean geometry was synthetic a priori, and that our experience must be as of a Euclidean
spacetime
.
But the
Minkowski
spacetime
in relativity is non-Euclidean.
Slide11Einstein
How do you respond to opponents (classical physics) that think their theory is knowable in advance of any argument or evidence?
Slide12Einstein
Einstein responded by operationalizing: imagining rigid rods extending in all directions, and clocks at various points.
That is, his arguments were couched in terms of what you could measure or experience (rather than straightforwardly in terms of what was true).
Slide13Einstein’s Operationalism
“The
destiny of General Relativity as a
physical
theory depends entirely upon the interpretation
of the ds [distance between two points in a reference frame] as
result of measurement, which can be
obtained in
a very quite definite way through measuring-rods
and clocks”
-- Einstein, Letter to Cassirer, June 1920
Slide14Quantum Mechanics
Quantum
mechanics also had metaphysical problems of its own. Several counterintuitive experiments seemed to suggest that the basic laws of the universe were not quite consistent with the laws of logic.
Slide15Quantum Mechanics
This led some physicists to simply deny that there were questions to be answered beyond “what do we observe/ experience?”– no questions like “what is the reality causing the appearances?”
Slide16Slide17Wilhelm Wundt
“Father of experimental psychology”
Founded first lab to study psychological phenomenon
Was an “
introspectionist
,” focused on individuals reporting details of their conscious experience.
Slide18Wilhelm Wundt
Wundt required his subjects to perform 10,000 introspective observations before they were considered sufficiently trained.
His student, Titchener wrote 1000 page training manual for experimental introspection.
Slide19Introspectionism
Training was supposed to provide subjects with
:
An increased capacity for attention
An ability to properly distinguish such facets of experience as ‘tonal intensity’ and ‘tonal clearness’
An ability to avoid confusions such as ‘stimulus error’ – the description of the object experienced as opposed to the experience itself.
Slide20Famously, however, none of the psychological labs got the same results! For example, they couldn’t agree whether one could introspect imageless thoughts.
Slide21John B. Watson
American psychologist
1878-1958
Progenitor of methodological behaviorism
Slide22Psychology as the Behaviorist Views It
In “Psychology as the Behaviorist Views It,” Watson
characterizes
psychology as:
‘purely objective’
‘a branch of natural science’
Concerned with ‘prediction and control of behavior’
NOT concerned with conscious states
Opposed to introspection
Recognizing no difference between human and animal
Slide23Watson vs. Introspectionism
“If you fail to reproduce my findings, it is not due to some fault in your apparatus or in the control of your stimulus, but it is due to the fact that your introspection is untrained… If you can't observe 3-9 states of clearness in attention, your introspection is poor.” (pg. 6).
Slide24Behaviorism
The
conclusion Watson draws
is:
we must get rid of all references to
consciousness. We shouldn’t use terms like ‘mental state’, ‘consciousness’, ‘mental image’, or even ‘mind’.
These aren’t
scientific terms.
The
vocabulary of psychology should only involve terms for behavior, stimulus, and so on.
Slide25Behaviorism
“[P]
sychology
as a behaviorist views it is a purely objective experimental branch of natural science. Its theoretical goal is … prediction and control”
Slide26Logical Positivism
Slide27Classical Empiricism
Last
time we learned about the idea theory.
Although
it wasn’t confined to the empiricists, most of
the important ones– Locke, Berkeley, and Hume– believed in it.
Slide28Classical Empiricism
“All ideas come from experience.”
“All knowledge comes from experience.”
“All ideas and all knowledge come from experience.”
Slide29Classical Empricism
Empiricism had its problems, in addition to those that the idea theory suffered from:
Modal Knowledge
: Experience tells you what is, not what must be/ should be/ will be. Yet we can know some of these things.
Poverty of the Stimulus
: We figure out things like language use faster than experience is capable of teaching us. This suggests innateness.
Slide30Positivism
The
French philosopher/ first Western sociologist
Isidore Auguste Marie François Xavier Comte
(1798-1857) theorized that society progressed in three stages
:
Theological
Metaphysical
Positive
Slide31Theological Stage
In
the theological stage, people believe any silly or magical thing their ancestors attributed to the gods.
Slide32Metaphysical Stage
Next
, in the metaphysical stage gods go out of the picture, but are replaced with unjustified “metaphysical”
assumptions.
Example: universal human rights.
Slide33Positivism
Finally
, in the positive stage, the truth of our beliefs is “positively” determined.
For
Compte
, science
was the only source of positive determination.
Slide34Logical Positivism
Around
the 1920’s in Vienna and Berlin certain philosophical doctrines became popular, and their adherents were variously known as Logical Empiricists or Logical Positivists
or sometimes neo-Positivists.
Slide35Slide36Empiricist Criterion of Cognitive Significance
According to the logical positivists, in order for a sentence to have cognitive significance (to be meaning
ful
), it had to have
verification conditions
.
Slide37Empiricist Criterion of Cognitive Significance
‘Verification’ is a Latinate English word < ‘
veri
-’ true + ‘
facere
’ to make.
Verification conditions are
conditions under which the truth of a statement can be conclusively established
.
Slide38Example: “The House is on Fire”
Slide39Empiricist Criterion of Cognitive Significance
In fact, the positivists maintained that the meaning of a sentence
was
its verification conditions.
So a sentence with no verification conditions– where no experience can establish its truth– is meaningless.
Slide40Truth vs. Verification
Many philosophers (even today) have identified the meaning of a sentence with its
truth
conditions. These are the circumstances in which
the sentence would be true
.
But the positivists went farther– they held that the meaning of a sentence was its
verification
conditions– the circumstances in which
we would know the sentence was true
.
Slide41The Elimination of Metaphysics
This was part of a radical philosophical agenda, which included “the elimination of metaphysics.”
The idea was to view many philosophical problems of the past (and also many religious claims) as meaningless disputes that could simply be ignored.
Slide42Anti-Religion
Example
: In a religion where God is beyond human experience, the positivists would say that “God exists” is neither true nor false but meaningless, since no experience could verify it.
Slide43Anti-Metaphysics
Kant
, Hegel, and Heidegger were also big targets for the positivists.
Example
Hegel quote:
“
But the other side of its Becoming, History, is a conscious, self-meditating process — Spirit emptied out into Time.”
Slide44The Elimination of Metaphysics
The positivists even wanted to eliminate a lot of more down-to-Earth metaphysics:
Modality
: We can only experience what is, not what could possibly be. So statements about what is (merely) possible are meaningless.
Normativity
: We can only experience what is, not what should morally be. So statements about what is good or bad are meaningless.
Slide45Metaphysics! Metaphysics!
Slide46Verificationist Semantics
Slide47Empiricist Semantics
According to the positivists, the elimination of metaphysics followed from the correct account of meaning.
When we understood that meaning = verification conditions, then we would see that ‘the Absolute is perfect’ or ‘God exists’ can’t possibly have meanings.
Then we would be free to look into more promising, resolvable philosophical questions.
Slide48Observation Sentences
We single out a certain, small set of sentences to be the “protocol” or “observation” sentences. These sentences are all very simple syntactically, along the lines of: ‘that is red.’
Slide49Immediate Experience
RED
PAIN
LOUD
THREE
Slide50TABLE
DOG
MOUNTAIN
CHAIR
Slide51Observation Sentences
The importance of the observation sentences is that they can be
immediately verified
.
To tell whether ‘that is red’ is verified (is true), you just have to
look
.
Slide52Non-Observation Sentences
All the other meaningful sentences (according to the verificationist) are defined in terms of the protocol sentences and the logical vocabulary (AND, OR, NOT, ALL, SOME, NO, etc.).
Slide53Definition of ‘Arthropod’
Example
‘
That is an arthropod’
:=
def
That
is an animal
AND
it has a jointed body
AND
it has segmented legs.
Slide54Non-Observation Sentences
Obviously these sorts of definitions work best with scientific terminology like ‘arthropod,’ but the positivists were happy with that.
It could turn out that much of our ordinary talk was not
strictly speaking
meaningful, but needed to be regimented in a more scientific language.
Slide55Observation Sentences
There was some measure of debate among the positivists regarding which sentences actually qualified as observation sentences.
The simpler the qualities they are about (e.g. ‘that is red’ ‘that is warm’ ‘this is joy’) the easier it is to argue that they can be verified immediately, but the harder it is to define the rest of the sentences.
Slide56Observation Sentences
Try
defining
“CY Leung is the chief executive of Hong Kong”
in terms of what things are red, warm, joy, etc.!
Slide57Observation Sentences
On the other hand, it’s easier to define more abstract things if we let sentences like ‘That is a chair’ or ‘That is a person’ be observation sentences.
However, can these things really be immediately verified?
Slide58Our observations don’t seem to
guarantee
that something is a gorilla (it might be a man in a costume, or the reflection of a gorilla, or…)
Slide59The Aufbau
In
the
Aufbau
(
The Logical Structure of the World),
Carnap
undertook an ambitious project to outline how one could translate all “high-level” talk (e.g. “the train to Vienna is running late”) into talk about sensations at coordinate points in the visual field (“quality q is at point-instant
x;y;z;t
”
Slide60Verificationist Semantics
So here’s the picture:
#1. The meaning of a sentence is the set of experiences that would verify it.
#2. Observation sentences are directly connected with their verification conditions: we can immediately tell whether they are verified in any particular circumstance.
#3. Non-observation sentences inherit their verification conditions from the observation sentences they are logically constructed out of.
Slide61Special Exception
One exception was made: logic and mathematics were held to be meaningful, even though its hard to state (for example) what experiences would confirm “2 + 2 = 4.”
Slide62Theoretical Entities
Slide63Theoretical Concepts
Verificationism
was thought to have particular trouble with theoretical concepts (that is, with representing theoretical entities) like electrons or DNA.
Slide64Verificationism vs. Theoretical Entities
These
are called “theoretical entities” because we can’t observe them directly, but their existence is confirmed by their characteristic effects as described by our scientific theories
.
Example
: effects of charged particles in cloud chambers
.
Slide65Verificationism vs. Theoretical Entities
The positivist can say
that the behavior of the gas in the cloud chamber verified the existence of electrons, even though it didn’t resemble them.
Slide66The Problem
The
problem was that the meanings of scientific terms was supposed to be fixed in advance
.
Yet for many theoretical terms, it took years or decades after their introduction for us to discover any way of verifying claims about them.
Slide67The Problem
Consider the claim:
“DNA has a double-helical structure.”
This claim seems to be meaningful.
Slide68The Problem
But Watson and Crick had to
discover
how to verify it.
Slide69The Problem
So positivism seems to suggest that claims about DNA, electrons, positrons, Higgs Bosons, or whatever did not mean anything until we discovered ways of verifying them.
At that time we
discovered
their meanings.