For tomorrow, read LB, pp' 99106 chapter 4, section 3'

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• For tomorrow, read LB, pp. 99-106 (chapter 4,
  section 3).

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Classical View of Theories

• -Scientific theories should be thought of as
  formal, axiomatic systems (like geometry or
  algebra).
• -The vocabulary of a theory is divided into
  theoretical and observable terms (or predicates).
• -Correspondence rules connect theoretical terms
  (or statements) with observational terms (or
  statements), so that predictions can be derived
  from the purely theoretical axioms, and the
  theory can be tested.

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Layer-Cake View of the Structure of Science

• Each lower layer in the cake can be deduced from
  the higher one (but not vice versa). So, from
  higher to lower, the relation is logical.
• Heading from lower to higher, the relation is one
  of confirmation based on observations. These
  relations presuppose correspondence rules.

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Scientific Progress

• On the classical view of theories, there is
  genuine scientific progress. We move closer to
  the logical unity of science represented by the
  layer cake
• First-level description of the data
• Second-level identification of patterns in the
  data.
• Third-level and beyond explanation of larger and
  larger patterns by more and more general
  theoretical principles (axioms, theorems)
  together with more and more refined
  correspondence rules.

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Objections

• 1. According to the classical view, theories are
  axiomatic systems.
• But typically there is more than one way to
  axiomatize the same theory. So, this cannot be
  the right way to understand scientific theories.
• Besides, scientists dont write out their
  theories in this way.

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Responses

• Different ways of axiomatizing the same theory
  commit to the same set of statements. Take the
  axioms and theorems of each formulation as a
  total set, and the various sets will be the same.
• Moreover, we might look to the practices working
  scientists to guide our choice of an
  axiomatization, but its philosophys job, not
  sciences, to figure out the ultimate
  structure(s) behind scientific practice.

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2. Doubts about Theory-Neutral Observation

• The classical view of theories depends on the
  distinction between theoretical terms and
  observational terms. Correspondence rules are
  supposed to connect theoretical terms with purely
  observational terms.
• But isnt observation always (or almost always)
  affected by the observers theoretical
  commitments? Isnt observation theory-laden?

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Example The Suns Movement

• To the average person, it looks as if the sun
  moves across the sky.
• But to the person who understands and works with
  the heliocentric (sun-centered) model, it may
  literally look as if the world is turning
  relative to a stationary sun.

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Another Example The Altered Playing Cards

• Experimenters made some spades red and some
  hearts black. They flashed the cards to subjects
  (at very short exposures).
• Most subjects report that there is nothing wrong
  (for example, they call the black ten of hearts a
  ten of hearts). Even when the subjects are given
  the playing cards to examine, a small percentage
  never recognizes the problem.

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What Are Such Cases Supposed to Prove?

• That observation is affected by theories and
  expectations, and thus that all terms are
  theoretical terms.
• If all terms are theoretical, scientific progress
  cant be grounded in any firm set of
  observational facts. Scientific change is not a
  matter of accounting for the same data in new and
  better ways.

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Are the Examples Convincing?

• -case of the sun?
• -case of the cards?
• More generally, even if scientists often
  categorize or label data in a theory-laden way,
  isnt there always a neutral perspective they can
  adopt that allows them to compare the virtues of
  competing theories?

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Relativism about Goals

• It might be that a theoretical characterization
  of the observational data results in different
  explanatory tasks for different theorists.
• A flying arrow arcs toward the ground.
• For Aristotle, the movement toward the ground
  needs no explanation this is natural. One needs
  to explain why the arrow flies at all.
• For Newton, the movement through the air needs no
  explanation. One needs to explain why the arrow
  falls.

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• But everyone can agree that the arrow is moving
  through the air those are the neutral
  observational facts.
• Then each group of scientists gets to
  characterize this in terms of their own
  theoretical vocabulary and see whether they can
  predict it, explain it, etc. Cant the success of
  these enterprises be compared even if the
  vocabulary differs from one group to another?

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3. Shift in Meaning of Terms

• Historical context helps to determine the very
  meaning of the terms used by previous generations
  of scientists.
• So, a representation of the structure of science
  now (e.g., the layer cake) should not presuppose
  that prior uses of these terms contribute what we
  would take them to contribute.

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Where Is the Conflict with Classical View?

• With regard to observations Be very careful
  about the use of old data.
• With regard to theory Dont be tricked into
  thinking that a less general theory has been
  confirmed in the past, then is later accommodated
  by a more general theory that applies the same
  terms or concepts.

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Responses

• With regard to observations Isnt it enough to
  look at the historical context to double-check
  the meaning? Werent the measurements taken often
  reported accurately enough in terms that we can
  understand now?
• With regard to theory The refinement of axioms
  as well as correspondence rules should
  accommodate the critics concern. Isnt such
  refinement itself a part of scientific progress?