CONCRETE IMPOSSIBLE WORLDS

Martin VacekInstitute of Philosophy

Slovak Academy of Sciencesmartinvacekphilosophy@gmail.com

www.martinvacek.com

Oklahoma Graduate Conference, Norman, 30/03/2013

Plan Exposition of modal realism

Applications of the theory

Why to bother with Impossibilia?

An Argument against Impossible Worlds

Proposals

Modal RealismWhat there is?

Concrete actual individualsConcrete nonactual individualsConcrete possible worldsSets Principle of unrestricted

mereological summationRecombination principleThere are no IMPOSSIBILIA.

Modal Realism

An individual x is a world iff any parts

of x are spatiotemporally related to

Each other, and anything spatiotemporally related to any

part of x is itself a part of x

Possible Worlds: Why We Need Them?

Analysis of modality

Properties and Propositions

Counterfactuals

Beliefs

Knowledge

Problems – several pre-theoretical opinions

Impossible properties

Impossible propositions

Counterfactuals with impossible antecedents

Impossible beliefs

IMPOSSIBILIA TO THE

RESCUE(?)

An Argument against Concrete Impossible Worlds

1. There exists an impossible world at which (P and ~P).

2. At w ~P iff ~(at w, P)3. At w (P and ~P) iff at w P and ~(at w P). 4. To tell the alleged truth about the

contradictory things is not different from contradicting yourself.

5. There is no subject matter about which you can tell the truth by contradicting yourself.

ThereforeImpossible worlds do not exist.

An Argument against Concrete Impossible Worlds

1. There exists an impossible world at which (P and ~P).

2. At w ~P iff ~(at w, P)3. At w (P and ~P) iff at w P and ~(at w P). 4. To tell the alleged truth about the

contradictory things is not different from contradicting yourself.

5. There is no subject matter about which you can tell the truth by contradicting yourself.

ThereforeImpossible worlds do not exist.

An Argument against Concrete Impossible Worlds

1. There exists an impossible world at which (P and ~P).

2. At w ~P iff ~(at w, P)3. At w (P and ~P) iff at w P and ~(at w P). 4. To tell the alleged truth about the

contradictory things is not different from contradicting yourself.

5. There is no subject matter about which you can tell the truth by contradicting yourself.

ThereforeImpossible worlds do not exist.

An Argument against Concrete Impossible Worlds

1. There exists an impossible world at which (P and ~P).

2. At w ~P iff ~(at w, P)3. At w (P and ~P) iff at w P and ~(at w P) 4. To tell the alleged truth about the

contradictory things is not different from contradicting yourself.

5. There is no subject matter about which you can tell the truth by contradicting yourself.

ThereforeImpossible worlds do not exist.

An Argument against Concrete Impossible Worlds

1. There exists an impossible world at which (P and ~P).

2. At w ~P iff ~(at w, P)3. At w (P and ~P) iff at w P and ~(at w P) 4. To tell the alleged truth about the

contradictory things is not different from contradicting yourself.

5. There is no subject matter about which you can tell the truth by contradicting yourself.

ThereforeImpossible worlds do not exist.

An Argument against Concrete Impossible Worlds

1. There exists an impossible world at which (P and ~P).

2. At w ~P iff ~(at w, P)3. At w (P and ~P) iff at w P and ~(at w P) 4. To tell the alleged truth about the

contradictory things is not different from contradicting yourself.

5. There is no subject matter about which you can tell the truth by contradicting yourself.

ThereforeImpossible worlds do not exist.

Proposal(s)

If

there is subject matter about which you can tell the truth by contradicting

yourself

Proposal(s)

If

there is subject matter about which you can tell the truth by contradicting

yourself

Paraconsictent Approach

Paraconsictent Approach

(A , ¬A) ⊨ B

Paraconsictent Approach

(A , ¬A) ⊨ B

Paraconsictent Approach

(A , ¬A) ⊨ B

(A ∧ ¬A)

Proposal(s)• is it a justified and legitimate

pre-theoretical opinion that classical logic holds

unrestrictedly?

Proposal(s)• is it a justified and legitimate

pre-theoretical opinion that classical logic holds

unrestrictedly?• localising the applicability of the

overall logic

Proposal(s)• is it a justified and legitimate

pre-theoretical opinion that classical logic holds

unrestrictedly?• localising the applicability of the

overall logic• we barely have an idea of what it

means for a world to obey one logic rather than another

THANKS