Nursing Knowledge
Chapter 8
Logical positivism and mid-century philosophy of science
Presented by Justin Fallin
October 25, 2014
Professor: Dr. Tomlinson
BEF 644
History and Terminology
Empiricism
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Philosophical approach to learning about
knowledge with a belief that everything comes
from a person’s experience.
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Differs from Rationalism
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Logical Positivism
Rationalists: knowledge does not require
experience, observation, or experiments.
Empiricism: “our” knowledge of the world
Rationalism: knowledge of things in the world
(Risjord, 2010)
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Developed from empiricism.
Formed from philosophers in the Vienna Circle:
Schlick and Neurath , in Europe after the First
World War (Godfrey-Smith, 2003)
Peak of influence in the 1930s-1940s
Positivists believed:
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All meaningful statements required verification
If unverifiable, it is essentially useless
As a result, it leaned toward scientific method
Science is not observable- they wanted to
prove unobservable could be meaningful
(Risjord, 2010)
Theory in Nursing
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Postulates: basic terms of a theory
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Euclid’s Geometry
Propositions: parts of the definition of a theory
arranged deductively.
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Axioms: basic propositions assumed true but
not tested
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Theorems: propositions developed from
axioms that can be deduced
1.
2.
3.
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Postulates contain terms implicitly defined by
postulates
Theorems develop from those postulates
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Axioms proved all truths in geometry– thus,
becoming theorems
Axiom is true= theorem is true
Is it acceptable to assume all axioms to be
true?
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Core of Theory: postulates or axioms
Axioms: first set of proofs but not proven
Positivists would say yes because of observable
consequences
Implicit Definitions
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Euclid’s definitions required prior knowledge of
the terms
All words cannot be defined because they
would all reference each other
Primitive terms are left without specific
definitions to avoid this circularity
(Risjord, 2010)
Theory Structure
Received View
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If knowledge comes from experience, scientific
knowledge must be from observation
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Observational vocabulary: objective terms such
as “blue car,” “going 200 mph”
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Theoretical vocabulary
Axioms expressed in theoretical vocabulary
Bridge laws to relate theoretical and
observational terms (needed– theory of only
theoretical terms cannot be tested)
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Empirical: inductively finds observable
regularities
Theoretical: speculative, uses postulates to
form with theoretical terms
Hierarchy of Theory
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Theoretical vocabulary: cannot be verified
(observed) directly such as germs, air, wind
Scientific theory has the following structure:
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Scientific research goes in two directions:
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To prevent such biases, positivists defined two
terms:
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Theoretical/Experimental Law
Fundamental Laws: implicit definitions for
fundamental concepts. (Newton’s law of
motion)
Middle-range Theories: experimental law or
empirical generalizations. (apply Newton’s law
to the tides)
Ultimately, all laws can be reduced to physics
but this seemed impossible as one domain
cannot reduce to another.
(Risjord, 2010)
Explanation and Testing
Explanation
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Empirical regularities that show a consequence
of fundamental laws are “explained”
phenomenon
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Per Hempel, explanation requires:
1.
2.
3.
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Testing Theory
Empiricism says all theories are tested through
observation
Per received view, to test a theory:
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Event or empirical regularities to be explained
(explanadum)
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Number of general laws
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Set of initial conditions (2 & 3 are grouped
together= explanans)
Known as the deductive-nomological
conception of explanations
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Proposition can be observed as true or false
(hypothesis)
Bridge laws are required to deduce the
hypothesis
If the theory proves false, theory is mistaken in
some way
According to Popper, theories are never true so
scientists should be attempting to prove
theories false through testing
(Risjord, 2010)
Conclusion
• Received view became core to understanding scientific view.
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Using axioms, unobservables may be accepted to empiricists
• For positivists, scientific knowledge is the fundamental knowledge of the
laws of nature
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Good theories are explanatory
• Science should produce theory and test it
• Disciplines considered basic sciences should have their own body of laws,
consisting of theories and conceptual frameworks for that basic science
(Risjord, 2010)
References
• Godfrey-Smith, P. (2003). Theory and Reality. Chicago, IL: The University of
Chicago Press.
• Risjord, M. (2010). Nursing Knowledge. Ames, IA: Wiley-Blackwell.