|Thomas Kuhn's 1969 postscript
to his The Structure of Scientific Revolutions
was intended to answer critics of the book primarily in regards to three
- That the book suffers from a lack of
development and clarity as to its primary metaphor,
- That Kuhn's position is relativistic;
- That Kuhn confuses descriptive and
normative analysis of science.
The majority of his time is spent in
answering the first charge. He does this by centering in on two meanings
of "paradigm" and the implications of these meanings to his
the one hand, it stands for the entire constellation of beliefs, values,
techniques, and so on shared by the members of a given community.
On the other, it denotes one sort of element in that
constellation, the concrete puzzle-solutions which, employed as models
or examples, can replace explicit rules as a basis for the solution of
the remaining puzzles of normal science.
The first sense of the term, call it the sociological . . .
[while the second is] devoted to paradigms as exemplary past
To show the value in these two approaches,
he refines a number of aspects in his analysis:
- While the scientific communities can be
discussed without reference to their paradigms, those paradigms are
what the members share and, therefore, are what set them apart.
- Scientific communities are demarcated at
various levels--from the most global to the subdisciplinary.
- Community structures do change over
time; for example, the content of a single discipline now may have at
points in the past been distributed over a number of disciplines.
- A "disciplinary matrix" is
made up of those elements that are required for professional
- "Symbolic generalizations" are
those assumptions that can be expressed in logical expressions which
are shared by the discipline and that function as "laws" but
more often as "definitions" or tautologies. Revolutions tend
to call into question what were previously tautologies.
- The "metaphysical" elements of
paradigms simply means the shared beliefs that provide a community its
unquestioned metaphors, analogies, and models.
- A scientific discipline's values include
a commitment to simplicity, self-consistency, plausibility, and so
forth in evaluating its theories, even though these values work
themselves out differently in each individual person's application.
- This difference in response is what
makes both the stability of normal science and the questioning of anomalies
- Training new scientists through shared
exemplars is what makes it possible to acquire the faculty of seeing a
current problem as like another one. This knowledge, then, is made
possible through concrete situations not through learning general
- Group intuitions are what make group
membership a working reality, and such knowledge is analyzable because
it is embedded in its shared exemplars.
Kuhn's answer to the second charge is to
stress that just because differing paradigm communities are
incommensurable, it doesn't follow that communication is impossible.
Things shared in common permit communication, but one should remember that
the shared vocabulary of the differing communities may also reveal a
fundamental difference in understanding. Likewise, the process of
translating between the differing viewpoints doesn't commit someone to
internalizing the other viewpoint as one's own, but it does create a
situation in which the gestalt switch from one way of seeing to another is
made possible. Using an "evolutionary tree" image, Kuhn insists
that he is not a relativist if that commits him to saying that no
scientific progress is possible. However, he also admits that he is a
relativist if this means that "[t]here is, I think, no
theory-independent way to reconstruct phrases like 'really there'; the
notion of a match between the ontology of a theory and its 'real'
counterpart in nature now seems to me illusive in principle."
To the third charge, he insists that the
descriptive and the proscriptive overlap in best practice. A study of the
history of science carries with it an attempt to understand the most
- Is Kuhn a relativist? Is he an
- Does a removal of a telos from
science give up too much? Why would it not?
- Does Kuhn's defense of exemplars
contradict his analysis of how textbooks and scientific education give
an illusion of singular discoveries and of cumulative findings?
- Why does Kuhn seem to distance himself
from the his earlier language of "metaphysics,"
"mystical aesthetic," and "conversion experience"?
- Has Kuhn, by using his evolutionary tree
image, reversed himself in regards to his views of scientific
- Is Kuhn's notion of a paradigm shift
applicable to other fields? Has it rightly been adopted?
- Is it possible to separate out the
normative and the descriptive? Explain.