Phil 3318: Philosophy of Science September 08, 2004 Induction v. Deduction What’s wrong with the scientific method we were taught in Jr. High?

True induction Bacon’s Method: 1.Draw axioms from experience 1.Categorize instances of the phenomenon in question: existence, closely-related non- existence, degrees 2.Then Induction: reject all that is not present in the negative instances. 2.Derive new experiences from axioms (experimentation). 1.Seek contradictory instances. 2.Repeat

Rationalism Descartes’ Method:

Top Nine Questions in the Philosophy of Science. 1.Is science objective? 2.The Demarcation Problem 3.Reduction 4.What is a law? 5.Do laws exist independently of the instances over which they quantify? 6.Can we have probabilistic, ‘ceteris paribus’ or ‘exceptional’, laws? 7.What is an explanation? 8.What kind of reasoning do (should) scientists use? 9.Are the unobservable entities posited by science real?

Induction v Deduction Not Truth Preserving Ampliative Spectral (reasoning with probability) Truth Preserving Non-ampliative All or nothing (reasoning with necessity)

Ampliative I saw a white swan Therefore, all swans are white All swans are white. Therefore, the swan that I saw was white.

Probability We have 10 male and 10 female freshman in this class. Therefore, 50% of all freshmen are male 50% of all freshman are male Therefore, a freshman chosen at random has a 50% chance of being male.

Simplistic inductivist account of science. Quote on pg. 11 of Hempel 1.Observe and record all facts. 2.Analyze and classify these facts. 3.Derive generalizations about them inductively. 4.Further test those generalizations.

Problems Problems: 1.It would never get started 2.Auxiliary hypotheses influence categorization and observation. 3.There are no ‘formal’ or ‘mechanical’ rules for generating inductive hypotheses.

(Brief) History of Color Science Basic Schema:

Hermann von Helmholtz ( ) Short = Purple Middle = GreenLong = Red

Historical Note: In 1877, Ladd-Franklin became the first woman to attend (albeit unofficially) Johns Hopkins where she studied mathematics. She wrote a dissertation under the supervision of C.S. Pierce. It was published in 1883, but her Ph.D. was not awarded until 1926! Even though she had studied under Helmholtz and had published a great deal in psychological journals, she was never admitted to the American Psychological Association meetings to present her papers. While she lectured at John Hopkins, Columbia, Clark, Harvard and Chicago, she never held an official academic post, and she was rarely paid. Her book Color and Color Theories was finally published in 1929, one year before her death.

Ladd-Franklin ( ) IF stimulating the long-wavelength cone yields a red experience, and stimulating the middle-wavelength cone yields a green experience, THEN stimulating both the long and middle- wavelength cone would…. yield an experience of reddish-green

L-F’s argument (≈1892) IF stimulating the long-wavelength cone yields a red experience, and stimulating the middle-wavelength cone yields a green experience, THEN stimulating both the long and middle- wavelength cone would yield an experience of reddish-green Stimulating L and M yields an experience of yellow. THEREFORE, Helmholtz’s theory is NOT true Yellow does NOT look like reddish-green. THEREFORE, yellow is NOT reddish-green. Good Argument Right?

Why not? “Helmholtz deemed it illegitimate or at least untrustworthy to draw conclusions as to physiological processes from the direct psychological character of the sensations” -Von Kries

Helmholtz’s response IF stimulating the Long-wavelength cone yeilds a red experience, and stimulating the middle-wavelength cone yields a green experience, THEN stimulating both the Long and Middle- wavelength cone would yield an experience of reddish-green Stimulating L and M yields an experience of yellow. THEREFORE, Helmholtz’s theory is NOT true THEREFORE, Yellow is NOT reddish-green. Yellow does NOT look like reddish-green. BUT: One cannot draw conclusions about the physiology of color from this fact, so it does not follow that: yellow is not reddish-green or greenish-red.

Note: The Gestalt Psychologist David Katz made the phenomenology of color appearance the starting point for a theory of color (1908).

Problems Problems: 1.It would never get started 2.Auxiliary hypotheses influence categorization and observation. 3.There are no ‘formal’ or ‘mechanical’ rules for generating inductive hypotheses.