Lecture 9: Logical Positivism & Unity of Science


 I. Logical Positivism and Operationism

 Auguste Comte (1798-1857):
Law of Three Stages, induction, socially useful knowledge


Ernst Mach (1838-1916): Sensationistic Physics

1885 - Analysis of sensations: All of physical theory
and laws can be framed in terms of sensations

Scientific meaning is provided through functional
about the relationships between sensations

(eg. F=MxA) in quantifiable terms

Relativism is expected: Influenced Albert Einstein

Vienna Circle ~ 1925:
The marriage of logic and empiricism

Unification of Science along with the expulsion
of metaphysics and ethics was their goal

 Theoretical terms can be linked to observation
terms or "Protocol Sentences" through theoretical
statements of the relationships between such
observations and
theoretical constructs

 Verifiability principle: "The meaning of a proposition
is the method of its verification."
The truth or
meaning of a statement is to be found in the
verification (proof) made by

Laws of Science are summary statements about
regularly correlated observations and predictions

Explanation is found in the verification of determinations
or predictions


Three groups of Logical (Neo) Positivists,
supporters of:
Sensationism (phenomenalism),
"physical" Language &
Physicalism (realism)


Percy Bridgman (1882-1961): Operationism

1927 - The logic of modern physics

Operational analysis: "the concept is synonymous with the corresponding set of operations" needed to perform the observation (physical and mental operations)

This is not a method for definitions, but for analyzing or sharpening the meanings of concepts already in place

Phenomenalism: Knowledge is limited to an individual's observations


Operationism: S.S.Stevens (1935) & E.G.Boring (1936)

Terms must be defined operationally to be scientifically meaningful

The "'Operational definition', as practiced in psychology,
seeks to universalize the language community by
reducing a concept to an observation"


Experimental Methods: Statistical inference

 Ronald A. Fisher (1890-1962) ANOVA

We can make inferences about the world through
an examination of the probabilities
that our
experimental treatments are due solely to chance.

 Null Hypothesis: A statement that there is
no difference between treatments and controls.
Rejecting the Null does not mean proof or verification
of the experimental hypothesis, only a lack of falsification.


The Golden Age of Behaviorism: Theories of Learning

 Edward Chace Tolman (1886-1959):
Purposive behaviorism

Influenced by neo-realism and gestalt psychology

Purpose and hunger could be objectively observed

 Operational behaviorism examines the functional relationships between independent anddependent variables


Intervening variables: Theoretical constructs
representing hypothetical processes) which
enable the prediction of dependent variables.
For example: B=fx(S,P,H,T,A)

 Cognitive maps: Internal representations of
the external world which are often acquired
through "latent learning"

 Clark Leonard Hull (1884-1952): Letter To Spence
Mechanism & reductionism

Mathematization of psychology: "physics envy"

Quantifiable prediction and control are goals of psychology
Underlying realism (in opposition to Mach & Bridgman)

 Hypothetico-Deductivism: "Explicitly stated postulates" derived from a theory provide testable predictions of that theory.

sEr = sHr x D x V x K - sIr - Ir


Gordon W. Allport (1897-1967):
Personology & Personality

Visited Freud ~1920 and embarrassed himself with a story

1937 - Personality: A psychological interpretation

Paranjpe (1993): Style over substance & the loss of personhood

Personality vs. Personology: Two worldviews

Naturwissenschaften vs. Geisteswissenschaften


Personology is marked by understanding persons
through the "trilogy of mind" enabling them
to be
ethico-legal agents of responsibility

Trilogy of mind is comprised of cognition (thinking),
conation (willing) and affect (

1939- APA Presidential Address:

Science is "empirical, mechanistic, quantitative,
nomothetic, analytic, and uses operational concepts"

 "Why not allow psychology as a science is [that is]
... rational, teleological, qualitative, idiographic,
synoptic, and even non-operational


Personality is a dynamic organization of traits or dispositions

Cardinal traits: Ruling passions in all experience
Central trait: Behavioral themes such as aggressiveness
or sentimentality
Secondary traits: Less frequently displayed behaviors

Study on values: Examined 18,000 adjectives from
a standard dictionary

 1950 - The Historical Background of social psychology:
Hedonism, Egoism, Sympathy, Imitation,
The Crowd, Group mind

 1954 - The nature of prejudice



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