bangu _fiction and explanation.pdf

Post on 07-Jul-2018

225 Views

Category:

Documents

0 Downloads

Preview:

Click to see full reader

TRANSCRIPT

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 1/49

Explanatory Fictions

and

Fictional Explanations

Sorin Bangu

Univ. of BergenSorin.Bangu@fof.uib.no 

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 2/49

Can fictions explain?

- question of perennial interest

“one of the main and most controversial roles

that fictional assumptions may play” (Suarez 2009, 7) 

Fictionalism

- Vaihinger 1920s

- Van Fraassen 1980s (phil of math: H. Field 1980s)

- A. Fine 1990s

- M. Suarez 2000s: 2009 Bokulich, Elgin, Winsberg, Morrison, etc.:

scientists seem fine with a ‘yes’ answer 

2

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 3/49

Can fictions explain?

- question of perennial interest

“one of the main and most controversial roles

that fictional assumptions may play” (Suarez 2009, 7) 

Fictionalism

- Vaihinger 1920s

- Van Fraassen 1980s (phil of math: H. Field 1980s)

- A. Fine 1990s

- M. Suarez 2000s: 2009 Bokulich, Elgin, Winsberg, Morrison, etc.:

scientists seem fine with a ‘yes’ answer 

3

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 4/49

Can fictions explain?

• No: Vaihinger [Hempel, Salmon,…] 

• Yes: Bokulich, Elgin… [2009]

Cautious ‘yes’: in what circumstances  (new)

Account: two steps

1. fictional explanations2. fictional explanations ≈ (genuine) explanations

fictions fictional explanations (genuine) explanations

role in  should be accepted as

2nd part: case study; phase transitions inthermodynamics and SM

4

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 5/49

Can fictions explain? No

5

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 6/49

Can fictions explain? No

If SC doesn’t exist, then how is it that there are giftsunder the three?

Explanation :: Understanding

6

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 7/49

Can fictions explain? No

If vortices don’t exist, then how is it that the Moonmoves?

Explanation :: Understanding

7

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 8/49

Can fictions explain? No.

Because falsehoods don’t explain! 

If the EXPLANANS are false / fictions, then how is itthat the EXPLANANDUM holds / is true?

Explanation :: Understanding

8

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 9/49

Can fictions explain? No.

Because falsehoods don’t explain! 

If the EXPLANANS are false / fictions, then how is itthat the EXPLANANDUM holds / is true?

Explanation :: Understanding

total falsehoods: gross ‘cancellation effect’ 

Russell syllogism

bread is stone / milk

stone / milk is nourishing

bread is nourishing

9

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 10/49

Can fictions explain? No.

Because falsehoods don’t explain! 

If the EXPLANANS are false / fictions, then how is itthat the EXPLANANDUM holds / is true?

Explanation :: Understanding

idealizations / approximationspartial falsehoods: subtle ‘cancellation effect’ 

Scientific modeling

false / idealized explanans

true explanandum

total falsehoods: gross ‘cancellation effect’ 

Russell syllogism

bread is stone / milk

stone / milk is nourishing

bread is nourishing

10

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 11/49

Can fictions explain? No.

Because falsehoods don’t explain! 

If the EXPLANANS are false / fictions, then how is itthat the EXPLANANDUM holds / is true?

Explanation :: Understanding

idealizations / approximationspartial falsehoods: subtle ‘cancellation effect’ 

Scientific modeling

false / idealized explanans

true explanandum

total falsehoods: gross ‘cancellation effect’ 

Russell syllogism

bread is stone / milk

stone / milk is nourishing

bread is nourishing

11

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 12/49

Can fictions explain? No.

Because falsehoods don’t explain! 

If the EXPLANANS are false / fictions, then how is itthat the EXPLANANDUM holds / is true?

Explanation :: Understanding

idealizations / approximationspartial falsehoods: subtle ‘cancellation effect’ 

Scientific modeling

false / idealized explanans

true explanandum

total falsehoods: gross ‘cancellation effect’ 

Russell syllogism

bread is stone / milk

stone / milk is nourishing

bread is nourishing

‘Concerned’ v. ‘unconcerned’ with the truth 

[Winsberg 2009]

12

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 13/49

Can fictions explain? No.

Because falsehoods don’t explain! 

If the EXPLANANS are false / fictions, then how is itthat the EXPLANANDUM holds / is true?

Explanation :: Understanding

idealizations / approximationspartial falsehoods: subtle ‘cancellation effect’ 

Scientific modeling

false / idealized explanans

true explanandum

total falsehoods: gross ‘cancellation effect’ 

Russell syllogism

bread is stone / milk

stone / milk is nourishing

bread is nourishing

Hempel: no explanation

Salmon: no explanation

‘Concerned’ v. ‘unconcerned’ with the truth 

[Winsberg 2009]

13

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 14/49

Can fictions explain? No.

Because falsehoods don’t explain! 

Hempel

Explananas (L + IC)

Explanandum

Four conditions for anexplanation

… 

2. “empirical condition of

adequacy” = the sentencesconstituting the explanans mustbe true (1965, 248)

… 

Salmon

• Fictional entities and

fictional processes do not

meet the requirements ofgenuine physical processes

capable of transmitting a

mark.

• fiction F cannot be the

cause of some phenomenon

P—and hence explain P—if

F does not exist.

14

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 15/49

Can fictions explain? No.

Because falsehoods don’t explain! 

Hempel

Explananas (L + IC)

Explanandum

Four conditions for anexplanation

… 

2. “empirical condition of

adequacy” = the sentencesconstituting the explanans mustbe true (1965, 248)

… 

Salmon

• Fictional entities and

fictional processes do not

meet the requirements ofgenuine physical processes

capable of transmitting a

mark.

• fiction F cannot be the

cause of some phenomenon

P—and hence explain P—if

F does not exist.

Woodward, Strevens, etc. 15

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 16/49

Can fictions explain? No.

Because falsehoods don’t explain! 

H. Vaihinger

(1924). The philosophy of ‘as if’ (C. K. Ogden, Trans.).London: Kegan Paul. (Original work published 1911)

Explanation involving fictions Understanding

• “…the fiction induces only an illusion of

understanding” (p. xv)• “[F]iction (…) does not create real knowledge” (p. 88) 

16

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 17/49

A diagnostic

The Main Problem

true explananda

false / fictional explanans

17

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 18/49

A diagnostic

The Main Problem

true explananda

false / fictional explanans

Solution:

Fictional content is

eliminable

dispensable, etc.

18

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 19/49

A role for fictions in explanation

Key-question:can fictions explain?

why / when do scientists accept explanations in which the

fictional content of the explanans is (seems) ineliminable?

 starting point: the explanandum has fictional content too

- this situation manifests in a variety of ways- not always explicit

- some clear example later

19

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 20/49

A role for fictions in explanation

Key-question:can fictions explain?

why / when do scientists accept explanations in which the

fictional content of the explanans is (seems) ineliminable?

 starting point: the explanandum has fictional content too

- this situation manifests in a variety of ways- not always explicit

- a clear example in 2nd part

20

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 21/49

A role for fictions in explanation

• indirect, two steps

1. Fictional explanation

2. (Good) fictional explanation  genuine explanation

Fictional explanation

21

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 22/49

A role for fictions in explanation

Fictional explanations

• Cases when both the explanans and the explananda involve fictions

explananda too involve fictions

Explananda = ? ‘Phenomena’  – the Woodward & Bogen sense

Data v. phenomena

- ‘constructed’ out of measurement data -’shaped’ into such as to be invariant 

phenomena - not out there, but posited ‘fictional’ 

Bogen, J., and J. Woodward (1988)Saving the phenomena The Philosophical Review  97: 303-352.

22

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 23/49

A role for fictions in explanation

Fictional explanations

• Cases when both the explanans and the explananda involve fictions

explananda too involve fictions

Explananda = ? ‘Phenomena’  – the Woodward & Bogen sense

Data v. phenomena

- ‘constructed’ out of measurement data -’shaped’ into such as to be invariant 

phenomena - not out there, but posited ‘fictional’ 

Bogen, J., and J. Woodward (1988)Saving the phenomena The Philosophical Review  97: 303-352.

Data

‘Shaped’ into

phenomena

Phenomena

‘Constructed’ from data (such as to be invariant) 

Not out there, but posited

“phenomena (…) cannot be reported by

observational claims.” (p. 343, 306).

Fictions (concerned with the truth)

23

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 24/49

Can fictions explain?

Key-question 

why / when do scientistsaccept explanations inwhich the fictional content

of the explanans seems (is)ineliminable?

A:

- When the explananda are‘phenomena’ = also haveineliminable fictional

content.- So not  a worrisome caseof [false true]

Fictionalist principle

‘fictions in the explanandaallow fictions in theexplanans’ 

24

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 25/49

Can fictions explain?

Key-question 

why / when do scientistsaccept explanations inwhich the fictional content

of the explanans seems (is)ineliminable?

A:

- When the explananda are‘phenomena’ = also haveineliminable fictional

content.- So not  a worrisome caseof [false true]

Fictionalist principle

‘fictions in the explanandaallow fictions in theexplanans’ 

Monopoly principle

‘buy fictional property with

fictional money’

25

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 26/49

Can fictions explain?

true explananda[phenomena]

fictional/false explanans 

26

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 27/49

Can fictions explain?

fictional/false explananda[‘phenomena’] 

fictional/false explanans

true explananda[phenomena]

fictional/false explanans 

27

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 28/49

Can fictions explain?

fictional/false explananda[‘phenomena’] 

fictional/false explanans

fictionalexplanation

true explananda[phenomena]

fictional/false explanans 

28

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 29/49

Can fictions explain?

fictional/false explananda[‘phenomena’] 

fictional/false explanans

fictionalexplanation

acceptable when no genuine 

explanation exists = one in which the

explananda are phenomena, not

‘phenomena’ 

Fictionalist principle

‘fictions in explananda allow

fictions in the explanans’ 

true explananda[phenomena]

fictional/false explanans 

29

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 30/49

Example of fictional explanation

• Why does water boil?

30

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 31/49

Explanandum 

= ‘undergoing a phase transition’ 

the property of ‘changing state’: liquid  vapor (gas)

ice (solid)

- water’s capacity to undergo a ‘phase transition’

- water’s capacity to ‘cross coexistence line’ 

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

31

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 32/49

Explanandum 

= ‘undergoing a phase transition’ 

the property of ‘changing state’: liquid  vapor (gas)

ice (solid)

- water’s capacity to undergo a ‘phase transition’ 

- water’s capacity to ‘cross coexistence line’ 

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

32

“So, here is a problem for the theoreticalphysicist: prove that as you raise or lower the

temperature of water you have phase transitions to

water vapor or to ice. Now, that’s a tall order!

We are far from having such a proof. In fact

there is not a single type of atom or molecule for

which we can mathematically prove that it will

crystallize at low temperature. These problems are

 just too hard for us.”

(D. Ruelle 1991: 123-4) 

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 33/49

Explanandum 

= ‘undergoing a phase transition’ 

the property of ‘changing state’: liquid  vapor (gas)

ice (solid)

- water’s capacity to undergo a ‘phase transition’

- water’s capacity to ‘cross coexistence line’ 

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

33

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 34/49

Explanandum  = ‘undergoing a

phase transition’ 

1. Functionalize 

- Water’s capacity to undergo a phase transition = cross ‘coexistence line’ 

More precisely:

- Define a quantity called ‘free energy’: G = H – TS

- Crossing takes place if G behaves in a certain way = its derivative (tangent)varies discontinuously (Zemansky 1968, 347)

34

H

= enthalpy  of the

system = total energy= internal energy + pV

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 35/49

Explanandum 

= ‘undergoing a phase transition’ 

1. Functionalize 

- Water’s capacity to undergo a phase transition = cross ‘coexistence line’ 

More precisely:

- Define a quantity called ‘free energy’: G = H – TS

- Crossing takes place if G behaves in a certain way = its derivative (tangent)varies discontinuously (Zemansky 1968, 347)

35

H

= enthalpy  of the

system = total energy= internal energy + pV

T

= temperature

of the system

S

= entropy of the system

= system's ability to dowork

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 36/49

Explanandum 

= ‘undergoing a phase transition’ 

1. Functionalize 

- Water’s capacity to undergo a phase transition = cross ‘coexistence line’ 

More precisely:

- Define a quantity called ‘free energy’: G = H – TS

- Crossing iff G behaves in a certain way =

its derivative (tangent) varies discontinuously (Zemansky 1968, 347)

36

-‘singularity’ 

-‘kink’ -‘sharp corner’ 

(Stanley 1971, 31)

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 37/49

Explanandum = ‘undergoing a

phase transition’ 

1. Functionalize 

- phase transition = cross ‘coexistence line’ = G has a singularity (kink)

Explanans: water molecules + Statistical Mechanics (QSM)

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

37

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 38/49

Explanandum  = ‘undergoing a

phase transition’ 

1. Functionalize 

- phase transition = cross ‘coexistence line’ = G has a singularity (kink)

Explanans: water molecules + Statistical Mechanics (QSM) 

2. Find realizers + theory Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

38

)ln

(ln1

 Z 

V  Z G

  

 

 E r e Z 

   

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 39/49

Explanandum = ‘undergoing a

phase transition’ 

1. Functionalize 

- phase transition = cross ‘coexistence line’ = G has a singularity (kink)

Explanans: water molecules + Statistical Mechanics (QSM) 

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

39

)ln

(ln1

 Z 

V  Z G

  

 

 E r e Z 

   

 

G can’t have a singularity! 

Impossible to find one in principle(mathematical result)

Reduction is blocked at step 2: realizers +

theory

Boiling = case of emergence not

captured in the Kim-Chalmers model

-Not weak emergence

-Not strong emergence due to failure at

step 1

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 40/49

Explanandum = ‘undergoing a

phase transition’ 

1. Functionalize 

- phase transition = cross ‘coexistence line’ = G has a singularity (kink)

Explanans: water molecules + Statistical Mechanics (QSM) 

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

40

)ln

(ln1

 Z 

V  Z G

  

 

 E r e Z 

   

 

G can’t have a singularity! 

Impossible to find one in principle(mathematical result)

G depends on Z, so if G is to have

singularities, Z has to have singularities.

But Z can’t have singularities (isanalytic). Z is a finite sum of analytic

 functions (not having singularities), and

any finite sum of analytic functions is

analytic (no singularities) So G can’t have

singularities b.c. of Z.

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 41/49

Explanandum  = ‘undergoing a

phase transition’ 

1. Functionalize 

- phase transition = cross ‘coexistence line’ = G has a singularity (kink)

Explanans: water molecules + Statistical Mechanics (QSM) 

2. Find realizers + theory 

Water (H20) molecules

Statistical Mechanics (QSM)

“When all of this is in, we are entitled to the claim that [boiling] has been 

reduced to the [behavior of molecules].”

41

)ln

(ln1

 Z 

V  Z G

  

 

 E r e Z 

   

 

G can’t have a singularity! 

Impossible to find one in principle(mathematical result)

G depends on Z, so if G is to have

singularities, Z has to have singularities.

But Z can’t have singularities (isanalytic). Z is a finite sum of analytic

 functions (not having singularities), and

any finite sum of analytic functions is

analytic (no singularities) So G can’t have

singularities b.c. of Z (Kadanoff 2000)

“So, here is a problem for the theoreticalphysicist: prove that as you raise or lower the

temperature of water you have phase transitions to

water vapor or to ice. Now, that’s a tall order!

We are far from having such a proof. In fact

there is not a single type of atom or molecule for

which we can mathematically prove that it will

crystallize at low temperature. These problems are

 just too hard for us.”

(D. Ruelle 1991: 123-4) 

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 42/49

 

• Proof (!): Yang & Lee 1952, etc.)

•singularity problem

A phase transition = singularity in G

can be derived within QSM

if the system contains an infinite

number of particles

N infinite

N / V finite

(‘thermodynamic limit’) 

42

N = number of molecules

V = volume

“The existence of a phase transition requires an

infinite system. No phase transitions occur in

systems with a finite number of degrees of

freedom.” (Kadanoff 2000, 238)

Explanandum

Explanans

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 43/49

• ‘Solution’ (Yang & Lee 1952, etc.) 

•singularity problem

A phase transition = singularity in G

can be derived within QSM

if the system contains an infinite

number of particles

N infinite

N / V fin

(taking the ‘thermodynamic limit’) 

43

“The existence of phase transitions shows that we have to

be careful when we adopt a reductionist approach. Phase

transitions correspond to emerging properties.” 

(Prigogine 1997, 45)

A case of fictional explanation The explanandum has fictional content...

The explanans have fictional content-“no experiments, no matter how finely tuned, can ever determine

whether the ‘corners’ which bound [phase transitions] regions are

sharp or round” (Liu 2001, 328) 

- “the transition is neither ‘smooth’ nor ‘singular’” (Liu 1999, 103). 

-[singularities are] “artifacts”; “fictions”; “do not exist in reality”

(Liu 1999, S104)

- “the role of a singularity is to represent a phase change 

 phenomenon. Note that the term ‘phenomenon’ is used here in

the specific sense of Bogen and Woodward. “ (Bangu 2009, 49) 

Explanandum

Explanans

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 44/49

• ‘Solution’ (Yang & Lee 1952, etc.) 

•singularity problem

A phase transition = singularity in G

can be derived within QSM

if the system contains an infinite

number of particles

N infinite

N / V fin

(taking the ‘thermodynamic limit’) 

44

“The existence of phase transitions shows that we have to

be careful when we adopt a reductionist approach. Phase

transitions correspond to emerging properties.” 

(Prigogine 1997, 45)

A case of fictional explanation The explanandum has fictional content too

The explanans have fictional content-“no experiments, no matter how finely tuned, can ever determine

whether the ‘corners’ which bound [phase transitions] regions are

sharp or round” (Liu 2001, 328) 

- “the transition is neither ‘smooth’ nor ‘singular’” (Liu 1999, 103). 

-[singularities are] “artifacts”; “fictions”; “do not exist in reality”

(Liu 1999, S104)

- “the role of a singularity is to represent a phase change 

 phenomenon. Note that the term ‘phenomenon’ is used here in

the specific sense of Bogen and Woodward. “ (Bangu 2009, 499) 

Explanandum

Explanans

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 45/49

• ‘Solution’ (Yang & Lee 1952, etc.) 

•singularity problem

A phase transition = singularity in G

can be derived within QSM

if the system contains an infinite

number of particles

N infinite

N / V fin

(taking the ‘thermodynamic limit’) 

45

“The existence of phase transitions shows that we have to

be careful when we adopt a reductionist approach. Phase

transitions correspond to emerging properties.” 

(Prigogine 1997, 45)

A case of fictional explanation The explanandum has fictional content too

The explanans have fictional content-“no experiments, no matter how finely tuned, can ever determine

whether the ‘corners’ which bound [phase transitions] regions are

sharp or round” (Liu 2001, 328) 

- “the transition is neither ‘smooth’ nor ‘singular’” (Liu 1999, 103). 

-[singularities are] “artifacts”; “fictions”; “do not exist in reality”

(Liu 1999, S104)

- “the role of a singularity is to represent a phase change 

 phenomenon. Note that the term ‘phenomenon’ is used here in

the specific sense of Bogen and Woodward. “ (Bangu 2009, 499) 

Explanandum

Explanans

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 46/49

• ‘Solution’ (Yang & Lee 1952, etc.) 

•singularity problem

A phase transition = singularity in G

can be derived within QSM

if the system contains an infinite

number of particles

N infinite

N / V fin

(taking the ‘thermodynamic limit’) 

46

“The existence of phase transitions shows that we have to

be careful when we adopt a reductionist approach. Phase

transitions correspond to emerging properties.” 

(Prigogine 1997, 45)

A case of fictional explanation The explanandum has fictional content too

The explanans have fictional content-“no experiments, no matter how finely tuned, can ever determine

whether the ‘corners’ which bound [phase transitions] regions are

sharp or round” (Liu 2001, 328) 

- “the transition is neither ‘smooth’ nor ‘singular’” (Liu 1999, 103) 

-[singularities are] “artifacts”; “fictions”; “do not exist in reality”

(Liu 1999, S104)

- “the role of a singularity is to represent a phase change 

 phenomenon. Note that the term ‘phenomenon’ is used here in

the specific sense of Bogen and Woodward. “ (Bangu 2009, 499)

Explanandum

Explanans

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 47/49

Wrapping up:

how/when fictions can be explanatoryfictional/false explananda

[‘phenomena’] 

fictional/false explanans

fictionalexplanation

acceptable when no genuine 

explanation exists = one in which the

explananda are phenomena, not

‘phenomena’ 

Fictionalist principle

‘fictions in explananda allow

fictions in the explanans’ 

47

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 48/49

Wrapping up:

how/when fictions can be explanatory

singularity: fictional

infinite system: fictional

fictional/false explananda

[‘phenomena’] 

fictional/false explanans

fictionalexplanation

acceptable when no genuine 

explanation exists = one in which the

explananda are phenomena, not

‘phenomena’ 

no explanation exists in which the

explanandum = phase transition (a

real process!) is not represented as

a singularity (and the explanans

don’t involve an infinite system)

Fictionalist principle

‘fictions in explananda allow

fictions in the explanans’ 

48

8/19/2019 Bangu _Fiction and Explanation.pdf

http://slidepdf.com/reader/full/bangu-fiction-and-explanationpdf 49/49

Thank you

top related