Mortiz Schlick: Positivism and Realism

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Mortiz Schlick Positivism and Realism

• September 10, 2008

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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S
bears relation R to statements the truth or
falsity which can be determined directly by
simple observation.
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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S
bears relation R to statements the truth or
falsity which can be determined directly by
simple observation.
Relation R relation of verification or
falsification
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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S is
verified or falsified by statements the truth or
falsity which can be determined directly by
simple observation.
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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S is
verified or falsified by statements the truth or
falsity which can be determined directly by
simple observation.
Can determine in principle, or can determine in
practice?
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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S is
verified or falsified by statements the truth or
falsity which can be determined directly by
simple observation.
Why observation? What counts as direct simple
observation? Example This ball weighs 10 kg.
Observation 1 I put the ball on the scale, and
it read 10 kg. Observation 2 I seemed to be
moving what looked to be my hands towards the
circle-shaped patch of gray in my visual field
and then appeared to be grasping this patch of
gray and then appeared to move this patch towards
what appeared to be a scale, then on the front of
what appeared to be a scale, I saw the following
image 10 kg.
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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S is
verified or falsified by statements the truth or
falsity which can be determined directly by
simple observation.
Conclusive Verifiability A sentence S is
conclusively verified iff there is some finite,
consistent set O of observation statements such
that O deductively entails S. Inductive
Verifiability A sentence S is inductively
verified iff there is some finite, consistent set
O of observation statements such that O
inductively supports S.
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Basis For Verifiability Theory of Meaning A
non-analytic sentence, S, is meaningful iff S is
verified or falsified by statements the truth or
falsity which can be determined directly by
simple observation.
Question What does the Verifiability Principle
rule out as meaningless? (a) The Absolute is
full potentiality. (b) Murder is wrong. (c)
God exists. (d) God does not exist. (e)
Ultimately, there is only one substance.
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• what every scientist seeks, and seeks alone,
  arethe rules which govern the connection of
  experiences, and by which alone they can be
  predicted. Moritz Schlick

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Basics of Schlicks Account
Two Main Ideas I. Meaning as circumstances in
which a proposition is true. II. Meaning as the
way that I could verify the truth of a
proposition. III. Circumstance a collection of
sense experiences
a statement only has a specifiable meaning if
it makes some testable difference whether it is
true or false. (41)
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In Principle/In Practice
Ex. There are 10,000 foot mountains on the far
side of the moon.
A statement is meaningless if it is logically
impossible for its truth or falsity to make a
testable difference.
Ex. The Red/Green case
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Does Abe see green the same as George does?
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Objections 1. This doesnt rule out the
sentences the positivists wanted to rule out.
E.g., The Absolute is full potentiality. 2.
The Reliable Computer.
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Schlick a statement only has a specifiable
meaning if it makes some testable difference
whether it is true or false. (41)
Objection 1 Testability is different than
meaning. Schlicks Response. Rejoinder.
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Schlick a statement only has a specifiable
meaning if it makes some testable difference
whether it is true or false. (41)
Objection 2 If the meaning of a statement by a
scientist is simply claiming certain things about
that scientists sense experience, then these
statements are not refutable. Schlicks
Response All ice in this room is 0 degrees
C. If the ice (in this room) is in contact with
a thermometer, then the thermometer measures 0
degrees C.
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All ice in this room is 0 degrees C. If the
ice (in this room) is in contact with a
thermometer, then the thermometer measures 0
degrees C.

• Problems
• If the ice is never measured, then the
  conditional is true. Further, all other
  conditionals of this form are true, too. So the
  ice is every temperature.
• If the ice WERE in contact with a thermometer,
  then it WOULD measure 0 degrees C.
• Problem with impossible measurements.
• The sun is 6000 degrees C ?If the sun were in
  contact with a thermometer, then the thermometer
  would measure 6000 degrees C.

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