# The Revolutionary.. ‘If’ Victor Howard Dudman.

## Presentation on theme: "The Revolutionary.. ‘If’ Victor Howard Dudman."— Presentation transcript:

The Revolutionary.. ‘If’

Victor Howard Dudman

Mark Thakkar

Amyas Merivale

…and somebody else

The Principles of Ingsoc War is Peace Freedom is Slavery Ignorance is Strength

The Principles of Oxlog Sentence determines message Truth is a property of sentences ‘ ’If’ is ‘  ’

[A] If Oswald didn’t shoot Kennedy, somebody else did whines, we beat him [B] If Oswald doesn’t shoot Kennedy, somebody else will [C] If Oswald hadn’t shot Kennedy, somebody else would have

If James whines, we beat him whines, we beat him

If James whines, we beat him whines, we beat him

Hypothetical message (Logical)

If James whines, we beat him whines, we beat him Habitual message

If James whines, we beat him whines, we beat him Fantasy message

If the door was locked, Grannie jumped in through the window Hypothetical message (Logical)

If the door was locked, Grannie jumped in though the window whines, we beat him Habitual message

If she misses the last bus, Her Majesty will walk home Fantasy message

If she misses the last bus, Her Majesty will walk home Habitual message

Stand Alone If P, then Q There is an antecedent

If Oswald didn’t shoot Kennedy, somebody else did whines, we beat him.Oswald didn’t shoot Kennedy. (YES)

If Her Majesty misses the last bus, she will usually walk home.Her Majesty misses the last bus. (NO)

If the vicar annoys Grannie again, she will show no mercy.The vicar annoys Grannie again. (NO)

Contraposition If P, then Q If not Q, then not P

If Oswald didn’t shoot Kennedy, somebody else did whines, we beat him If nobody else shot Kennedy, then Oswald did (YES)

If Her Majesty misses the last bus, she will usually walk home If Her Majesty will not usually walk home, she doesn’t miss the last bus. (NO)

If the vicar annoys Grannie again, she will show no mercy If Grannie will show mercy, the vicar doesn’t annoy Grannie again. (NO)

Time and Tense Tense: time registered by form Time: time the message is about

If Oswald didn’t shoot Kennedy, somebody else did whines, we beat him Tense: Past Time: Past (Tense = Time)

If Her Majesty misses the last bus, she will usually walk home whines, we beat him Tense: Present Time: Present (Tense = Time)

If the vicar annoys Grannie again, she will show no mercy Tense: Present Time: Future (Tense < Time)

If Grannie commits suicide, she will make it look like murder Tense: Present Time about: Future

If Grannie commited suicide, she would make it look like murder Tense: Past Time about: Future

If the accountants had come tomorrow, they would have found our books in order Tense: Past past Time about: Future

If Oswald doesn’t shoot Kennedy, somebody else will Tense: Present Time about: Future

If Oswald hadn’t shot Kennedy, somebody else would have. Tense: Past Past Time about: Past

Logical messages Pass Stand-Alone Contrapose Tense = Time

Habitual messages Fail Stand-Alone Don’t contrapose Tense = Time

Fantasy messages Fail Stand-Alone Don’t contrapose Tense < Time

Non-logical hypothetical messages The dog – if it was a dog – ran off If it rained, it didn’t rain hard If the Mayor is married, his wife did not accompany him

Non-logical hypothetical messages If it didn’t run off, it wasn’t a dog If it rained hard, it didn’t rain If his wife did accompany him, the Mayor is not married

Non-logical hypothetical messages Pass Stand-Alone Don’t Contrapose Tense = Time

[A] If Oswald didn’t shoot Kennedy, somebody else did whines, we beat him [B] If Oswald doesn’t shoot Kennedy, somebody else will [C] If Oswald hadn’t shot Kennedy, somebody else would have

Logical messages … … are condensed arguments

If P, then Q P. So Q

If Oswald didn’t shoot Kennedy …then somebody else did

Oswald didn’t shoot Kennedy So: Somebody else did

Logical messages Cannot have truth-values Their standard is deductive validity

Habitual messages Do have truth-values They are propositions - claims of fact about their tenses.

Fantasy messages Cannot have truth-values Are not propositions Are justified by inductive reasoning

The Bad News Almost every prelim examination over the last few years has misunderstood all this.

The Good News Your tutors can cope

20 September 480 B.C.

The Battle of Salamis

DATELINE 19 SEPTEMBER THE EVE OF THE BATTLE

Artful Themistocles

DATELINE 20 SEPTEMBER THE DAY OF THE BATTLE

Brave Aristides

DATELINE 21 SEPTEMBER THE DAY AFTER THE BATTLE

Herodotus Father of Greek History

Aeschylus Father of Greek Tragedy

?

What the fuck?

I mean, er.. what the fucking fuck?

We are young men and women of high spirit and noble ideals. We are philosophers, interested in the semantics of English ‘if’. What in God’s name are we doing here?

Aristotle De Interpretatione

De Interpretatione 9 "With regard to what is and what has been it is necessary for the affirmation or the negation to be true or false.....................But with particulars that are going to be it is different."

DATELINE 19 SEPTEMBER THE EVE OF THE BATTLE

[19A] There will be a sea- battle tomorrow

[19B] There will be a sea- battle tomorrow even if a storm destroys the Persian fleet overnight

DATELINE 20 SEPTEMBER THE DAY OF THE BATTLE

[20A] There is a sea-battle going on now

[20B] There is a sea-battle going on now even if a storm destroyed the Persian fleet overnight

DATELINE 21 SEPTEMBER THE DAY AFTER THE BATTLE

[21A] There was a sea- battle yesterday

[21B] There was a sea- battle yesterday even if a storm destroyed the Persian fleet the night before

[1] LOGIC PAST: There was a battle yesterday PRESENT: There is a battle (raging) now FUTURE: There will be a battle tomorrow

[2] TRUTH-VALUE PAST: There was a battle yesterday PRESENT: There is a battle (raging) now FUTURE: There will be a battle tomorrow

[3] NEGATION PAST: There was a battle yesterday There was no battle yesterday PRESENT: There is a battle (raging) now There is no battle (raging) now FUTURE: There will be a battle tomorrow There might be no battle tomorrow

‘Will’ and ‘Will not’ are not contradictories They are contraries

Messages about the Future Are Fantasy messages Cannot have truth-values Are not propositions – claims of fact about their tenses They are ……

Judgements

Fin

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