various

1
various

• 1. organise extra seminar

2
The Special Sciences

• Their domain is limited economics psychology
  biology
• These disciplines seem to involve laws
• exceptions are not explicable in terms of the
  special science in question
• Sellers and buyers may be crazy
• Crazy is not an economic category

3
Arguments for the autonomy of the special sciences

• (i) economics not reducible to physical science
• Each economic events has a physical description
• But all price rises, say, have nothing physical
  in common
• And units of money have nothing physical in
  common
• Economic generalisations cannot therefore be
  captured by laws couched in physical terms

4

• Economics, though, still involves laws Laws of
  Economics (and not physics)
• Cf. positivist conception of science all
  respectable sciences must reduce to physics

5
(ii) Putnams round and square pegs

• Why does a round peg fit into a round hole and
  not a square one
• 2 explanations
• (i) because it is the same shape and size
• (ii) a complex explanation involving the
  positions of all the subatomic particles that
  make up the peg and the hole

6

• (i) applies across a wide range of cases it is a
  more general explanation
• (i) could therefore be used to predict what would
  happen in relevantly similar cases
• It is counterfactual supporting thus a law
• But round pegs have nothing physical in common
• They have something geometric in common

7

• I am suggesting, roughly, that there are special
  sciences not because of the nature of our
  epistemic relation to the world, but because of
  the way the world is put together not all
  natural kinds (not all classes of things and
  events about which there are important,
  counterfactual supporting generalisations to make
  (are, or correspond to, physical natural kinds.
  (Fodor, Special Sciences, 113)

8
The unification of Science

• science is unified in that all sciences will
  reduce to physics
• Weaker conception of unification
• The laws of the special sciences cannot be
  reduced to those of physics
• But all economic events, say, can be given a
  physical description

9

• It seems to methat the classical construal of
  the unity of science has really misconstrued the
  goal of scientific reduction. The point of
  reduction is not primarily to find some natural
  kind predicate of physics co-extensive with each
  natural kind predicate of a reduced science. It
  is, rather, to explicate the physical mechanisms
  whereby events conform to the laws of the special
  sciences. (Fodor, Special Sciences, 107)

10

• If science is to be unified, then all such
  taxonomies those of the special sciences must
  apply to the same things. If physics is to be the
  basic science, then each of these things had
  better be a physical thing. But it is not further
  required that the taxonomies which the special
  sciences employ must themselves reduce to the
  taxonomy of physics. It is not required, and it
  is probably not true. (Fodor, Special
  Sciences, 114)

11
Can biology be reduced to physics?

• biology is a varied discipline
• We shall focus on genetics
• The inheritance of traits
• Two kinds of genetics
• 1. Mendelian genetics
• 2. Molecular genetics

12

• Reduction of genetics to physics would be via
  various steps
• Mendelian genetics ? molecular genetics ?
  biochemistry ? chemistry ? physics

13
Mendelian Genetics

• Gregor Mendel and sweet peas
• Phenotype the outward appearance of offspring
• Crossing a red and a blue sweet pea produces
  offspring with various phenotypes red, blue
  white sweet peas
• Why?
• Theoretical explanation
• (Theoretical not a pejorative term)
• Theories explain the observed phenomena in terms
  of the unobserved

14
The Gene

• These explain phenotypic differences
• Genes come in pairs, one from each parent

15
Eye colour

• Gene B codes for brown eyes
• Gene b codes for blue eyes
• If you are BB then you have brown eyes
• If you are bb then you have blue eyes
• homozygous
• But what if you are Bb?
• Heterozygous
• One gene dominates the other
• B is dominant
• b is recessive
• If you are Bb then you have brown eyes

16
Laws of genetics

• BB BB parents
• B B sex cells
• BB offspring
• all brown

17

• BB bb parents
• B b sex cells
• Bb offspring
• all brown

18

• Bb Bb parents
• B b B b sex cells
• BB Bb bB bb offspring
• ¾ brown ¼ blue

19
complexities

• Traits coded for by multiple genes
• Pleiotropy same gene affecting lots of traits
• mutations

20
Reduction to molecular genetics

• What will need to be explained in molecular
  terms?
• What is required is a molecular description of
  Mendelian processes and properties
• 1. e.g. genes, dominance, heterozygous
• 2. The laws of genetics