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PHIL202: Philosophy of Science

Unit 2: Observation, Theory-Ladenness, and Objectivity   “[U]nless we make default assumptions, the world would simply make no sense.  It would be as useless to perceive how things ‘actually look’ as it would be to watch the random dots on untuned television screens.  What really matters is being able to see what things look like.” [1]

Observation, whether performed in a natural or an experimental environment, is one of the key sources of scientific evidence.  Popular discussions of science often suppose that the information obtained through observation has a kind of objectivity that information obtained by faith or personal revelation does not.  But does it?  Some, such as Carl Hempel, maintain that observational evidence is especially objective by virtue of being directly and intersubjectively accessible.  Others, such as Norwood Russell Hanson, argue that background theoretical assumptions always influence the results of observation, and that this “theory-ladenness” renders observational evidence irremediably subjective.  Still others, such as Israel Scheffler, argue that theory-ladenness does not compromise the objectivity of observational evidence.


[1] Marvin Minsky, The Society of Mind (New York: Simon & Schuster, 1985), 247 (italics in original).

Unit 2 Time Advisory
This unit should take approximately 10 hours to complete.

☐    Subunit 2.1: 1 hour

☐    Subunit 2.2: 4 hours

☐    Subunit 2.3: 2 hours

☐    Subunit 2.4: 3 hours
 

☐    Readings: 1 hour

☐    Assessment 2: 2 hours

Unit2 Learning Outcomes
Upon completion of this unit, the student will be able to: - Summarize Hempel’s account of the nature of observation. - Identify some of the key ways in which observation is theory-laden, as well as some of the evidence that supports the view that observation is theory-laden. - Summarize and assess key arguments regarding whether observation provides a basis for scientific objectivity.

2.1 The Nature of Observation   - Reading: Stanford Encyclopedia of Philosophy: Jim Bogen’s “What Do Observation Reports Describe?” Link: Stanford Encyclopedia of Philosophy: Jim Bogen’s “What Do Observation Reports Describe?” (HTML)

 Instruction: Please click on the above link, which directs you to
the second section of Bogen’s article “Theory and Observation in
Science.”  In this section, Bogen summarizes Carl Hempel’s views
about the nature of observation.  An account of the nature of
observation does not characterize the physical and mental processes
involved in observing the world; nor does it characterize the
methods we use to perform observations.  Instead, an account of the
nature of observation characterizes what it is that gets observed
when an observation happens.  Hempel’s account of the nature of
observation is the background for subsequent philosophical
discussions regarding the objectivity of observation (discussions
that you will study in the remainder of this section).  

 Hempel provides an indirect account of the nature of observation
with an account of the nature of observation reports.  An
“observation report” is a spoken or written sentence that records an
observation; and since these sentences describe the content of
observation, we can determine the nature of observation by
determining what it is that observation reports describe.  Bogen
summarizes both Hempel’s account of the nature of observation as
well as Hempel’s criticisms of a competing, phenomenalist account.  

 As you read Bogen’s summary, answer the following questions in
order to verify your understanding of the material: What is the
phenomenalist account of the nature of observation—that is,
according to the phenomenalist account, what gets observed when an
observation happens?  What are some limitations of this account? 
What is Hempel’s account, and how does his account avoid the
limitations of the phenomenalist account?  

 Reading this selection and answering these questions should take
approximately 1 hour.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

2.2 The Theory-Ladenness of Observation   2.2.1 The Philosophical Case for Theory-Ladenness   - Reading: Norwood Russell Hanson’s Patterns of Discovery: “Chapter 1: Observation” Link: Norwood Russell Hanson’s Patterns of Discovery: “Chapter 1: Observation” (HTML)

 Instructions: Please click on the above link and read the entire
chapter.  

 Hanson begins this chapter with a brief discussion of situations in
which two scientists, present at roughly the same spatiotemporal
location and attentive to roughly the same objects and events at
that location, differ in how they characterize the experience. 
These situations raise the question: Do the scientists have the same
experience, merely described in different language; or do their
experiences differ?  

 Hanson dismisses phenomenalist-style appeals to mental states and
sense data to answer this question, according to which scientists
have the same experiences because they have roughly the same sense
data; and he dismisses appeals to variations of interpretation,
according to which the scientists have different interpretations of
the same experience.  He then defends the thesis that the scientists
have different experiences, and he locates the source of this
difference, not in the objects themselves, but rather in the context
each scientist brings to the object.  In a scientific setting, these
contexts typically involve theoretical commitments and concepts as
well as other higher-order forms of knowledge.  These concepts,
Hanson argues, lead the scientists to organize the elements of their
experience differently; and so, Hanson concludes, the scientists’
experiences differ by virtue of being theory-laden.  (“Theory,” in
this context, is used in a very broad sense to refer not only to
scientific theories but also to naïve theories, mental models,
perceptual schemata, and so on.)  

 As you read this chapter, attempt to answer the following
questions: Why does Hanson dismiss appeals to sense data as
providing an answer to his central question?  Why does he dismiss
appeals to variations of interpretation?  What does he take the
various figures that appear in his chapter to show?  Finally, what
reasons does he provide for the thesis that observation is a
theory-laden undertaking?  

 Reading this chapter and answering these questions should take
approximately 2 hours.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.
  • Reading: Loyola University New Orleans: Henry Folse’s “The Theory-Ladenness of Observation” Link: Loyola University New Orleans: Henry Folse’s “The Theory-Ladenness of Observation” (HTML)

    Instructions: Please click on the above link and read the lecture notes in their entirety.

    Folse’s lecture notes clarify and elaborate upon some of the concepts and positions involved in philosophical discussions of the nature of observation: sense data theory (also known as phenomenalism); physicalism (the view Hempel advocates); and theory-ladenness.  You should focus your reading on understanding these ideas.  Later course units will cover, in more detail, other ideas from Folse’s lecture notes, such as confirmation and theory choice.  Accordingly, while you should read Folse’s notes in their entirety, read with the aim of achieving some clarification of the prior readings in this course unit as well as some orientation to the significance of discussions about the nature of observation.

    Reading these notes and relating them to prior material will take approximately 1 hour.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

2.2.2 Psychological Evidence for Theory-Ladenness   - Reading: University of Illinois at Chicago: William Brewer and Bruce Lambert’s “The Theory-Ladenness of Observation and the Theory-Ladenness of the Rest of the Scientific Process” Link: University of Illinois at Chicago: William Brewer and Bruce Lambert’s “The Theory-Ladenness of Observation and the Theory-Ladenness of the Rest of the Scientific Process” (PDF)

 Instructions: The above link directs you to a list of Bruce
Lambert's conference presentations from 2000, the first listing of
which is titled “The Theory-Ladenness of Observation and the
Theory-Ladenness of the Rest of the Scientific Process.” Click the
link “[view .pdf]” at the end of that listing, and read the
paper.   

 Brewer and Lambert examine evidence from cognitive psychology and
the history of science in order to determine whether there is
empirical support for the thesis that observation is theory-laden. 
What evidence do they find?  What conclusions about theory-ladenness
do they draw from this evidence?  

 Reading this paper and answering these questions should take
approximately 1 hour.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

2.3 Theory-Ladenness and Objectivity   2.3.1 The Ideal of Objectivity and the Threat of Theory-Ladenness   - Reading: Israel Scheffler’s “Objectivity Under Attack” Link: Israel Scheffler’s “Objectivity Under Attack” (HTML)

 Instructions: Please click on the above link and read the chapter
in its entirety.  

 Scheffler characterizes the ideal of objectivity, explains why
satisfaction of this ideal is important to the authority of science,
and discusses challenges to the idea that objectivity in scientific
inquiry is possible.  Some of these challenges are based upon the
claim that observation is theory-laden (refer to the previous
reading from Hanson for details).  Scheffler indicates that he
suspects these challenges must be mistaken; he does not, however, in
this chapter, indicate his reasons for rejecting the challenges.  

 You should read this chapter with the following questions in mind:
What is the ideal of objectivity?  Why is satisfaction of this ideal
important?  How does the thesis of theory-ladenness challenge the
possibility of satisfying this ideal in scientific inquiry?  

 Reading this chapter and answering these questions should take
approximately 1 hour.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

2.3.2 The Compatibility of Theory-Laden Observation and Objectivity   - Reading: Digital Text International: Eugene Lashchyk’s “Facts Are Paradigm-Laden” Link: Digital Text International: Eugene Lashchyk’s “Facts Are Paradigm-Laden” (HTML)

 Instructions: Please click on the above link and read the chapter
in its entirety.  

 In this selection from his book *Scientific Revolutions*, Lashchyk
addresses two questions: (1) Does the claim that there is no neutral
observation language imply that there is no independent and
objective reality that must be taken into account by our scientific
theories?  (2) Does it imply that there is no independent check on
the creation of our conceptual schemes?  He answers each question in
the negative, arguing (contrary to Scheffler’s worries in the
preceding reading selection) that the theory-ladenness of
observation does not compromise the objectivity of science.  

 Although Lashchyk frames his discussion as a response to Thomas
Kuhn’s idea that observation is determined by a scientist’s
paradigm, the discussion is relevant to Hanson’s idea that
observation is theory-laden.  For Kuhn’s idea (which you will learn
about in more detail later in this course) is an elaboration of
Hanson’s idea: *paradigms* include not only theories (in Hanson’s
sense) but also scientific practices and attitudes.  Accordingly,
you may take Lashchyk’s argument to be addressing concerns about the
objectivity of science in light of the theory-ladenness of
observation.  Focus specifically on the reasons Lashchyk offers for
maintaining that theory-laden observations can support the rejection
of current theories and the development of new theories.  (The
relevant discussion begins just over halfway through Lashchyk’s
paper.)  

 Reading this chapter and relating the content to prior material
will take approximately 1 hour.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

2.4 Review of Observation, Theory-Ladenness, and Objectivity   - Assessment: The Saylor Foundation: “Assessment 2” Link: The Saylor Foundation: “Assessment 2” (PDF)

 Instructions: This assessment will ask you to apply and assess key
views and arguments regarding the nature of observation and whether
the theory-ladenness of observation compromises the objectivity of
scientific inquiry.  Use the [“Assessment 2 – Guide to
Responding”](http://www.saylor.org/site/wp-content/uploads/2012/10/PHIL202-Unit2-Assessment2-Guide-FINAL.pdf)
(PDF) to help you.  Please check your essays against the
[“Assessment 2 – Self-Assessment
Rubric”](http://www.saylor.org/site/wp-content/uploads/2012/10/PHIL202-Unit2-Assessment2-Rubric-FINAL.pdf)
(PDF).  

 Completing this assessment will take approximately 1 hour.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.
  • Reading: Wayne State University: M. Nissani and D.M. Hoefler-Nissani’s “When Theory Fails” Link: Wayne State University: M. Nissani and D.M. Hoefler-Nissani’s “When Theory Fails” (HTML)

    Instructions: Please click on the link above and read the article in its entirety.  The assessment to follow makes reference to this article.

    Reading this article will take approximately 1 hour.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.