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Obligations and The Responsio Antiqua : Positio Disputations Stephen Read In positio the Opponent presents: Obligations Disputations ◮ A casus : a hypothetical background situation Walter Burley Obligational ◮ A positum : a proposition, which may be accepted or Disputations The Responsio rejected by the Respondent Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Antiqua : Positio Disputations Stephen Read In positio the Opponent presents: Obligations Disputations ◮ A casus : a hypothetical background situation Walter Burley Obligational ◮ A positum : a proposition, which may be accepted or Disputations The Responsio rejected by the Respondent Antiqua Positio ◮ A sequence of propositions which may be granted, Burley’s thesis An Obligational denied or doubted (or in later texts, distinguished as Sophism The Responsio ambiguous) by the Respondent, according to the rules Nova Roger Swyneshed of positio Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Antiqua : Positio Disputations Stephen Read In positio the Opponent presents: Obligations Disputations ◮ A casus : a hypothetical background situation Walter Burley Obligational ◮ A positum : a proposition, which may be accepted or Disputations The Responsio rejected by the Respondent Antiqua Positio ◮ A sequence of propositions which may be granted, Burley’s thesis An Obligational denied or doubted (or in later texts, distinguished as Sophism The Responsio ambiguous) by the Respondent, according to the rules Nova Roger Swyneshed of positio Swyneshed’s Theses Swyneshed’s theory ◮ the obligation ends when either Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Antiqua : Positio Disputations Stephen Read In positio the Opponent presents: Obligations Disputations ◮ A casus : a hypothetical background situation Walter Burley Obligational ◮ A positum : a proposition, which may be accepted or Disputations The Responsio rejected by the Respondent Antiqua Positio ◮ A sequence of propositions which may be granted, Burley’s thesis An Obligational denied or doubted (or in later texts, distinguished as Sophism The Responsio ambiguous) by the Respondent, according to the rules Nova Roger Swyneshed of positio Swyneshed’s Theses Swyneshed’s theory ◮ the obligation ends when either Other Types of ◮ the Respondent grants and denies the same proposition Obligation Institutio (or grants a contradiction), or Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Antiqua : Positio Disputations Stephen Read In positio the Opponent presents: Obligations Disputations ◮ A casus : a hypothetical background situation Walter Burley Obligational ◮ A positum : a proposition, which may be accepted or Disputations The Responsio rejected by the Respondent Antiqua Positio ◮ A sequence of propositions which may be granted, Burley’s thesis An Obligational denied or doubted (or in later texts, distinguished as Sophism The Responsio ambiguous) by the Respondent, according to the rules Nova Roger Swyneshed of positio Swyneshed’s Theses Swyneshed’s theory ◮ the obligation ends when either Other Types of ◮ the Respondent grants and denies the same proposition Obligation Institutio (or grants a contradiction), or Petitio ◮ when the Opponent says ‘ cedat tempus ’, i.e., time’s up Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Antiqua : Positio Disputations Stephen Read In positio the Opponent presents: Obligations Disputations ◮ A casus : a hypothetical background situation Walter Burley Obligational ◮ A positum : a proposition, which may be accepted or Disputations The Responsio rejected by the Respondent Antiqua Positio ◮ A sequence of propositions which may be granted, Burley’s thesis An Obligational denied or doubted (or in later texts, distinguished as Sophism The Responsio ambiguous) by the Respondent, according to the rules Nova Roger Swyneshed of positio Swyneshed’s Theses Swyneshed’s theory ◮ the obligation ends when either Other Types of ◮ the Respondent grants and denies the same proposition Obligation Institutio (or grants a contradiction), or Petitio ◮ when the Opponent says ‘ cedat tempus ’, i.e., time’s up Depositio Dubitatio Sit Verum ◮ there may follow an analysis of how well the Conclusion Respondent responded. Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed ◮ granted if it follows Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed ◮ granted if it follows Swyneshed’s Theses Swyneshed’s theory ◮ denied if it is inconsistent Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed ◮ granted if it follows Swyneshed’s Theses Swyneshed’s theory ◮ denied if it is inconsistent Other Types of ◮ if not, i.e., if it’s irrelevant, it is not obligated and Obligation Institutio (given the casus ) should be Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed ◮ granted if it follows Swyneshed’s Theses Swyneshed’s theory ◮ denied if it is inconsistent Other Types of ◮ if not, i.e., if it’s irrelevant, it is not obligated and Obligation Institutio (given the casus ) should be Petitio Depositio ◮ granted if (known to be) true, Dubitatio Sit Verum Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed ◮ granted if it follows Swyneshed’s Theses Swyneshed’s theory ◮ denied if it is inconsistent Other Types of ◮ if not, i.e., if it’s irrelevant, it is not obligated and Obligation Institutio (given the casus ) should be Petitio Depositio ◮ granted if (known to be) true, Dubitatio Sit Verum ◮ denied if (known to be) false and Conclusion Summary References

Obligations and The basic rules of positio Disputations Stephen Read Obligations ◮ In possible positio , the positum should be accepted only Disputations if it could be true. Walter Burley Obligational Disputations ◮ If the proposition follows from or is inconsistent with The Responsio Antiqua the positum and/or something already granted/denied, Positio it is said to be “relevant” ( pertinens ), otherwise Burley’s thesis An Obligational Sophism “irrelevant” ( impertinens ) The Responsio ◮ if it is relevant, it is “obligated” and should be Nova Roger Swyneshed ◮ granted if it follows Swyneshed’s Theses Swyneshed’s theory ◮ denied if it is inconsistent Other Types of ◮ if not, i.e., if it’s irrelevant, it is not obligated and Obligation Institutio (given the casus ) should be Petitio Depositio ◮ granted if (known to be) true, Dubitatio Sit Verum ◮ denied if (known to be) false and Conclusion ◮ doubted if it is not known whether it is true or false. Summary References

Obligations and An Example of Possible Positio Disputations Stephen Read Obligations Disputations Walter Burley Obligational Disputations The Responsio 0. Positum : ‘Every man is running’ Accepted Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and An Example of Possible Positio Disputations Stephen Read Obligations Disputations Walter Burley Obligational Disputations The Responsio 0. Positum : ‘Every man is running’ Accepted Antiqua Positio 1. ‘Every man is running’ Granted (the positum ) Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and An Example of Possible Positio Disputations Stephen Read Obligations Disputations Walter Burley Obligational Disputations The Responsio 0. Positum : ‘Every man is running’ Accepted Antiqua Positio 1. ‘Every man is running’ Granted (the positum ) Burley’s thesis An Obligational Sophism 2. ‘You are running’ Denied (irrelevant and false) The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and An Example of Possible Positio Disputations Stephen Read Obligations Disputations Walter Burley Obligational Disputations The Responsio 0. Positum : ‘Every man is running’ Accepted Antiqua Positio 1. ‘Every man is running’ Granted (the positum ) Burley’s thesis An Obligational Sophism 2. ‘You are running’ Denied (irrelevant and false) The Responsio Nova 3. ‘You are a man’ Denied (true, but inconsistent Roger Swyneshed with the positum and the oppo- Swyneshed’s Theses Swyneshed’s theory site of what has been denied) Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Impossible positio Disputations Stephen Read The early treatises, up until Burley and Ockham, also accepted impossible positio , where the positum is impossible: Obligations Disputations Walter Burley Obligational ◮ However, the positum must not be explicitly Disputations contradictory, but must be credible: The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Impossible positio Disputations Stephen Read The early treatises, up until Burley and Ockham, also accepted impossible positio , where the positum is impossible: Obligations Disputations Walter Burley Obligational ◮ However, the positum must not be explicitly Disputations contradictory, but must be credible: The Responsio Antiqua ◮ E.g., ‘God is not God’, ‘A man is an ass’ can be Positio Burley’s thesis accepted An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Impossible positio Disputations Stephen Read The early treatises, up until Burley and Ockham, also accepted impossible positio , where the positum is impossible: Obligations Disputations Walter Burley Obligational ◮ However, the positum must not be explicitly Disputations contradictory, but must be credible: The Responsio Antiqua ◮ E.g., ‘God is not God’, ‘A man is an ass’ can be Positio Burley’s thesis accepted An Obligational Sophism ◮ Not every consequence should be granted; e.g., in The Responsio Nova impossible positio one must not use the “rule of the Roger Swyneshed Swyneshed’s Theses Adamites”, viz that from the impossible anything Swyneshed’s theory follows, nor the rule that what is necessary follows from Other Types of Obligation anything Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Impossible positio Disputations Stephen Read The early treatises, up until Burley and Ockham, also accepted impossible positio , where the positum is impossible: Obligations Disputations Walter Burley Obligational ◮ However, the positum must not be explicitly Disputations contradictory, but must be credible: The Responsio Antiqua ◮ E.g., ‘God is not God’, ‘A man is an ass’ can be Positio Burley’s thesis accepted An Obligational Sophism ◮ Not every consequence should be granted; e.g., in The Responsio Nova impossible positio one must not use the “rule of the Roger Swyneshed Swyneshed’s Theses Adamites”, viz that from the impossible anything Swyneshed’s theory follows, nor the rule that what is necessary follows from Other Types of Obligation anything Institutio Petitio ◮ But one can use syllogistic inferences and rules of Depositio Dubitatio transposition Sit Verum Conclusion Summary References

Obligations and Impossible positio Disputations Stephen Read The early treatises, up until Burley and Ockham, also accepted impossible positio , where the positum is impossible: Obligations Disputations Walter Burley Obligational ◮ However, the positum must not be explicitly Disputations contradictory, but must be credible: The Responsio Antiqua ◮ E.g., ‘God is not God’, ‘A man is an ass’ can be Positio Burley’s thesis accepted An Obligational Sophism ◮ Not every consequence should be granted; e.g., in The Responsio Nova impossible positio one must not use the “rule of the Roger Swyneshed Swyneshed’s Theses Adamites”, viz that from the impossible anything Swyneshed’s theory follows, nor the rule that what is necessary follows from Other Types of Obligation anything Institutio Petitio ◮ But one can use syllogistic inferences and rules of Depositio Dubitatio transposition Sit Verum Conclusion ◮ Is impossible positio useful? Yes, says Ockham: “by Summary References such positio one opens the way to recognising which inferences are good and self-evident and which are not.”

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio 1. ‘You are not in Rome or you are Granted (irrelevant and the Antiqua a bishop’ first disjunct is true) Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio 1. ‘You are not in Rome or you are Granted (irrelevant and the Antiqua a bishop’ first disjunct is true) Positio Burley’s thesis An Obligational 2. ‘You are a bishop’ Granted (follows from the Sophism positum and what was The Responsio Nova granted) Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio 1. ‘You are not in Rome or you are Granted (irrelevant and the Antiqua a bishop’ first disjunct is true) Positio Burley’s thesis An Obligational 2. ‘You are a bishop’ Granted (follows from the Sophism positum and what was The Responsio Nova granted) Roger Swyneshed ◮ or like this: Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio 1. ‘You are not in Rome or you are Granted (irrelevant and the Antiqua a bishop’ first disjunct is true) Positio Burley’s thesis An Obligational 2. ‘You are a bishop’ Granted (follows from the Sophism positum and what was The Responsio Nova granted) Roger Swyneshed ◮ or like this: Swyneshed’s Theses Swyneshed’s theory 0. Positum : ‘You are in Rome’ Accepted Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio 1. ‘You are not in Rome or you are Granted (irrelevant and the Antiqua a bishop’ first disjunct is true) Positio Burley’s thesis An Obligational 2. ‘You are a bishop’ Granted (follows from the Sophism positum and what was The Responsio Nova granted) Roger Swyneshed ◮ or like this: Swyneshed’s Theses Swyneshed’s theory 0. Positum : ‘You are in Rome’ Accepted Other Types of Obligation 1. ‘“You are in Rome” and “You Granted (irrelevant and Institutio are a bishop” are alike in truth- true—they are both false) Petitio Depositio value’ Dubitatio Sit Verum Conclusion Summary References

Obligations and Burley’s thesis, or rule Disputations ◮ Burley observes that in possible positio , the Respondent Stephen Read can be forced to grant any other false proposition Obligations compatible with the positum . E.g., to prove you are a Disputations bishop: Walter Burley Obligational Disputations 0. Positum : ‘You are in Rome’ Accepted (possible) The Responsio 1. ‘You are not in Rome or you are Granted (irrelevant and the Antiqua a bishop’ first disjunct is true) Positio Burley’s thesis An Obligational 2. ‘You are a bishop’ Granted (follows from the Sophism positum and what was The Responsio Nova granted) Roger Swyneshed ◮ or like this: Swyneshed’s Theses Swyneshed’s theory 0. Positum : ‘You are in Rome’ Accepted Other Types of Obligation 1. ‘“You are in Rome” and “You Granted (irrelevant and Institutio are a bishop” are alike in truth- true—they are both false) Petitio Depositio value’ Dubitatio Sit Verum 2. ‘You are a bishop’ Granted (follows from the Conclusion positum and what was Summary granted) References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis although in the previous example, when proposed in the An Obligational Sophism opposite order, (1) and (2) were granted. The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis although in the previous example, when proposed in the An Obligational Sophism opposite order, (1) and (2) were granted. The Responsio ◮ Indeed, responses can change: Nova Roger Swyneshed 0. Positum : ‘The king is sitting or you are running’ Accepted Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis although in the previous example, when proposed in the An Obligational Sophism opposite order, (1) and (2) were granted. The Responsio ◮ Indeed, responses can change: Nova Roger Swyneshed 0. Positum : ‘The king is sitting or you are running’ Accepted Swyneshed’s Theses Swyneshed’s theory 1. ‘The king is sitting’ Doubted (irrelevant and unknown) Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis although in the previous example, when proposed in the An Obligational Sophism opposite order, (1) and (2) were granted. The Responsio ◮ Indeed, responses can change: Nova Roger Swyneshed 0. Positum : ‘The king is sitting or you are running’ Accepted Swyneshed’s Theses Swyneshed’s theory 1. ‘The king is sitting’ Doubted (irrelevant and unknown) Other Types of 2. ‘You are running’ Denied (irrelevant and false) Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis although in the previous example, when proposed in the An Obligational Sophism opposite order, (1) and (2) were granted. The Responsio ◮ Indeed, responses can change: Nova Roger Swyneshed 0. Positum : ‘The king is sitting or you are running’ Accepted Swyneshed’s Theses Swyneshed’s theory 1. ‘The king is sitting’ Doubted (irrelevant and unknown) Other Types of 2. ‘You are running’ Denied (irrelevant and false) Obligation 3. ‘The king is sitting’ Granted (follows from the positum and Institutio Petitio the opposite of what has been denied) Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The theory is dynamic Disputations ◮ Burley’s theory is dynamic—the response can depend on the Stephen Read order in which propositions are proposed: e.g., Obligations 0. Positum : ‘You are in Rome’ Accepted Disputations Walter Burley 1. ‘You are a bishop’ Denied (irrelevant and false) Obligational Disputations 2. ‘“You are in Rome” and Denied (inconsistent with the The Responsio “You are a bishop” are alike positum and the opposite of Antiqua in truth-value’ what has been denied) Positio Burley’s thesis although in the previous example, when proposed in the An Obligational Sophism opposite order, (1) and (2) were granted. The Responsio ◮ Indeed, responses can change: Nova Roger Swyneshed 0. Positum : ‘The king is sitting or you are running’ Accepted Swyneshed’s Theses Swyneshed’s theory 1. ‘The king is sitting’ Doubted (irrelevant and unknown) Other Types of 2. ‘You are running’ Denied (irrelevant and false) Obligation 3. ‘The king is sitting’ Granted (follows from the positum and Institutio Petitio the opposite of what has been denied) Depositio Dubitatio ◮ However, although what has been doubted can later be granted Sit Verum or denied, grant can never turn into denial or vice versa. Conclusion Summary References

Obligations and The importance of the instant Disputations ◮ Burley emphasizes that “all responses must be for the same Stephen Read instant.” Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The importance of the instant Disputations ◮ Burley emphasizes that “all responses must be for the same Stephen Read instant.” Obligations ◮ For suppose at the start of the obligation, you are sitting, but Disputations having granted the irrelevant proposition ‘You are sitting’, you Walter Burley Obligational then stand up Disputations ◮ Should you now deny ’You are sitting’? The Responsio Antiqua ◮ If so, you have denied something you earlier granted, and so Positio you have responded badly Burley’s thesis An Obligational ◮ But if you grant it, you may have granted something irrelevant Sophism and false, and again you have responded badly The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The importance of the instant Disputations ◮ Burley emphasizes that “all responses must be for the same Stephen Read instant.” Obligations ◮ For suppose at the start of the obligation, you are sitting, but Disputations having granted the irrelevant proposition ‘You are sitting’, you Walter Burley Obligational then stand up Disputations ◮ Should you now deny ’You are sitting’? The Responsio Antiqua ◮ If so, you have denied something you earlier granted, and so Positio you have responded badly Burley’s thesis An Obligational ◮ But if you grant it, you may have granted something irrelevant Sophism and false, and again you have responded badly The Responsio ◮ You should grant it, even though it is now false, for it was true Nova Roger Swyneshed when you granted it, and “all responses must be for the same Swyneshed’s Theses instant.” Swyneshed’s theory ◮ It was usual to take the instant to be the start of the obligatio . Other Types of Obligation Suppose we call the instant A : Institutio 0. Positum : ‘The Antichrist exists’ Accepted Petitio Depositio 1. ‘The Antichrist exists at A ’ Denied (the Antichrist exists only Dubitatio in the future) Sit Verum 2. ‘It is A ’ Denied (inconsistent with the posi- Conclusion tum and the opposite of what has Summary been denied) References

Obligations and The importance of the instant Disputations ◮ Burley emphasizes that “all responses must be for the same Stephen Read instant.” Obligations ◮ For suppose at the start of the obligation, you are sitting, but Disputations having granted the irrelevant proposition ‘You are sitting’, you Walter Burley Obligational then stand up Disputations ◮ Should you now deny ’You are sitting’? The Responsio Antiqua ◮ If so, you have denied something you earlier granted, and so Positio you have responded badly Burley’s thesis An Obligational ◮ But if you grant it, you may have granted something irrelevant Sophism and false, and again you have responded badly The Responsio ◮ You should grant it, even though it is now false, for it was true Nova Roger Swyneshed when you granted it, and “all responses must be for the same Swyneshed’s Theses instant.” Swyneshed’s theory ◮ It was usual to take the instant to be the start of the obligatio . Other Types of Obligation Suppose we call the instant A : Institutio 0. Positum : ‘The Antichrist exists’ Accepted Petitio Depositio 1. ‘The Antichrist exists at A ’ Denied (the Antichrist exists only Dubitatio in the future) Sit Verum 2. ‘It is A ’ Denied (inconsistent with the posi- Conclusion tum and the opposite of what has Summary been denied) References However, although we must deny that it is A , that does not mean that ‘It is A ’ is false.

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio 2. ‘Something follows from the Granted (follows from Antiqua positum ’ what has been granted) Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio 2. ‘Something follows from the Granted (follows from Antiqua positum ’ what has been granted) Positio Burley’s thesis An Obligational 3. ‘Something was posited to ??? Sophism you’ The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio 2. ‘Something follows from the Granted (follows from Antiqua positum ’ what has been granted) Positio Burley’s thesis An Obligational 3. ‘Something was posited to ??? Sophism you’ The Responsio Nova 4. Cedat tempus Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio 2. ‘Something follows from the Granted (follows from Antiqua positum ’ what has been granted) Positio Burley’s thesis An Obligational 3. ‘Something was posited to ??? Sophism you’ The Responsio Nova 4. Cedat tempus Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory ◮ If you grant it, you grant the opposite of the positum , so Other Types of Obligation you respond badly Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio 2. ‘Something follows from the Granted (follows from Antiqua positum ’ what has been granted) Positio Burley’s thesis An Obligational 3. ‘Something was posited to ??? Sophism you’ The Responsio Nova 4. Cedat tempus Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory ◮ If you grant it, you grant the opposite of the positum , so Other Types of Obligation you respond badly Institutio ◮ If you deny it, you deny something that follows, so again Petitio Depositio you respond badly Dubitatio Sit Verum Conclusion Summary References

Obligations and Pragmatic Inconsistency Disputations Stephen Read 0. Positum : ‘Nothing is posited to you’ Accepted 1. ‘Everything that follows Granted (it’s a rule) Obligations Disputations from the positum must be Walter Burley Obligational granted’ Disputations The Responsio 2. ‘Something follows from the Granted (follows from Antiqua positum ’ what has been granted) Positio Burley’s thesis An Obligational 3. ‘Something was posited to ??? Sophism you’ The Responsio Nova 4. Cedat tempus Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory ◮ If you grant it, you grant the opposite of the positum , so Other Types of Obligation you respond badly Institutio ◮ If you deny it, you deny something that follows, so again Petitio Depositio you respond badly Dubitatio Sit Verum ◮ Solution: Burley says that step 1 should be denied: the Conclusion rule is that IF something follows from the positum it Summary References should be granted.

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: 0. Positum : ‘Every man is running’ Accepted Obligations Disputations 1. ‘Every man is running’ Granted (the positum ) Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: 0. Positum : ‘Every man is running’ Accepted Obligations Disputations 1. ‘Every man is running’ Granted (the positum ) Walter Burley 2. ‘You are a man’ Granted (irrelevant and true) Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: 0. Positum : ‘Every man is running’ Accepted Obligations Disputations 1. ‘Every man is running’ Granted (the positum ) Walter Burley 2. ‘You are a man’ Granted (irrelevant and true) Obligational Disputations 3. ‘You are running’ Denied (false and irrelevant) The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: 0. Positum : ‘Every man is running’ Accepted Obligations Disputations 1. ‘Every man is running’ Granted (the positum ) Walter Burley 2. ‘You are a man’ Granted (irrelevant and true) Obligational Disputations 3. ‘You are running’ Denied (false and irrelevant) The Responsio Antiqua Why is ‘You are running’ irrelevant? Not because it does not follow from Positio the positum and what has been granted. He says it does. But he denies Burley’s thesis An Obligational that the conjunction of (1) and (2) should be granted, that is, one can Sophism deny a conjunction both of whose conjuncts have been granted: The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: 0. Positum : ‘Every man is running’ Accepted Obligations Disputations 1. ‘Every man is running’ Granted (the positum ) Walter Burley 2. ‘You are a man’ Granted (irrelevant and true) Obligational Disputations 3. ‘You are running’ Denied (false and irrelevant) The Responsio Antiqua Why is ‘You are running’ irrelevant? Not because it does not follow from Positio the positum and what has been granted. He says it does. But he denies Burley’s thesis An Obligational that the conjunction of (1) and (2) should be granted, that is, one can Sophism deny a conjunction both of whose conjuncts have been granted: The Responsio Nova “This response puts forward these two rules. The first is: A Roger Swyneshed Swyneshed’s Theses conjunction may be denied each of whose parts should be Swyneshed’s theory granted. The second is that a disjunction may be granted each Other Types of Obligation of whose parts should be denied.” Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and The Responsio Nova Disputations Stephen Read Robert Fland tells us: “ Est tamen una alia responsio quasi nova . . . ”: 0. Positum : ‘Every man is running’ Accepted Obligations Disputations 1. ‘Every man is running’ Granted (the positum ) Walter Burley 2. ‘You are a man’ Granted (irrelevant and true) Obligational Disputations 3. ‘You are running’ Denied (false and irrelevant) The Responsio Antiqua Why is ‘You are running’ irrelevant? Not because it does not follow from Positio the positum and what has been granted. He says it does. But he denies Burley’s thesis An Obligational that the conjunction of (1) and (2) should be granted, that is, one can Sophism deny a conjunction both of whose conjuncts have been granted: The Responsio Nova “This response puts forward these two rules. The first is: A Roger Swyneshed Swyneshed’s Theses conjunction may be denied each of whose parts should be Swyneshed’s theory granted. The second is that a disjunction may be granted each Other Types of Obligation of whose parts should be denied.” Institutio The author of the responsio nova was Roger Swyneshed. Indeed, Paul of Petitio Depositio Venice plays on the name, speaking of oppinionem illorum quos porcinos Dubitatio vocat (“the opinion of those whom he [the master he is criticizing] calls Sit Verum Conclusion ‘swinish’).” Summary References

Roger Swyneshed (or Suisset) Obligations and Disputations Stephen Read ◮ Not to be confused with the better-known Merton Calculator, Richard Swyneshed (or Swineshead) Obligations ◮ Studied at Oxford under Thomas Bradwardine and Richard Disputations Walter Burley Kilvington Obligational Disputations ◮ Wrote treatises on Insolubles and Obligations between The Responsio Antiqua 1330 and 1335 (and also a treatise on Consequences now Positio apparently lost) Burley’s thesis An Obligational ◮ Author of Descriptiones motuum (or De motibus Sophism The Responsio naturalibus ), a treatise on natural changes, including Nova Roger Swyneshed locomotion Swyneshed’s Theses ◮ Subsequently became Master of Theology (though his Swyneshed’s theory Other Types of Sentences -lectures are also lost) Obligation ◮ Also a member of Richard de Bury’s circle Institutio Petitio ◮ A Benedictine monk of Glastonbury, died about 1365. Depositio Dubitatio Sit Verum Subtle Swyneshed, denizen of Glastonbury, Conclusion Indeed a monk of fond memory, Summary References Whose fame of industry has not perished, Suffered the poor to live in peace.

Obligations and Swyneshed’s Iconoclastic Theses Disputations Stephen Read Obligations In his treatise on Obligationes , Swyneshed presents two Disputations Walter Burley striking theses: Obligational Disputations ◮ “Having granted the parts of a conjunction, the The Responsio Antiqua conjunction need not be granted” Positio Burley’s thesis An Obligational ◮ “Nor having granted a disjunction, need either of its Sophism parts be granted.” The Responsio Nova Roger Swyneshed Yet in an obligational disputation, one must normally grant Swyneshed’s Theses whatever follows from what has already been granted. Swyneshed’s theory Other Types of ◮ What is Swyneshed’s new theory of obligations? Obligation Institutio ◮ Why does Swyneshed offer a new theory? Petitio Depositio Dubitatio ◮ Is Swyneshed’s theory a logical heresy? Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations 4. ‘Every man is running and you are Granted (since it is valid) The Responsio a man, so you are running’ Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations 4. ‘Every man is running and you are Granted (since it is valid) The Responsio a man, so you are running’ Antiqua Positio 5. ‘Every man is running and you are Denied † (irrelevant and false) Burley’s thesis An Obligational a man’ Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations 4. ‘Every man is running and you are Granted (since it is valid) The Responsio a man, so you are running’ Antiqua Positio 5. ‘Every man is running and you are Denied † (irrelevant and false) Burley’s thesis An Obligational a man’ Sophism 6. ‘Not every man is running or you Granted (equivalent to the The Responsio Nova are not a man’ opposite of (5)) Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations 4. ‘Every man is running and you are Granted (since it is valid) The Responsio a man, so you are running’ Antiqua Positio 5. ‘Every man is running and you are Denied † (irrelevant and false) Burley’s thesis An Obligational a man’ Sophism 6. ‘Not every man is running or you Granted (equivalent to the The Responsio Nova are not a man’ opposite of (5)) Roger Swyneshed 7. ‘Not every man is running or you are Granted (since it is valid) Swyneshed’s Theses Swyneshed’s theory not a man, but you are a man, so not Other Types of every man is running’ Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations 4. ‘Every man is running and you are Granted (since it is valid) The Responsio a man, so you are running’ Antiqua Positio 5. ‘Every man is running and you are Denied † (irrelevant and false) Burley’s thesis An Obligational a man’ Sophism 6. ‘Not every man is running or you Granted (equivalent to the The Responsio Nova are not a man’ opposite of (5)) Roger Swyneshed 7. ‘Not every man is running or you are Granted (since it is valid) Swyneshed’s Theses Swyneshed’s theory not a man, but you are a man, so not Other Types of every man is running’ Obligation Institutio 8. ‘Not every man is running or you are Denied (inconsistent with Petitio Depositio not a man, and you are a man’ the positum ) Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Central Example Disputations Stephen Read 0. Positum : ‘Every man is running’ Accepted 1. ‘Every man is running’ Granted (the positum ) Obligations 2. ‘You are a man’ Granted (irrelevant and true) Disputations Walter Burley 3. ‘You are running’ Denied † (irrelevant and false) Obligational Disputations 4. ‘Every man is running and you are Granted (since it is valid) The Responsio a man, so you are running’ Antiqua Positio 5. ‘Every man is running and you are Denied † (irrelevant and false) Burley’s thesis An Obligational a man’ Sophism 6. ‘Not every man is running or you Granted (equivalent to the The Responsio Nova are not a man’ opposite of (5)) Roger Swyneshed 7. ‘Not every man is running or you are Granted (since it is valid) Swyneshed’s Theses Swyneshed’s theory not a man, but you are a man, so not Other Types of every man is running’ Obligation Institutio 8. ‘Not every man is running or you are Denied (inconsistent with Petitio Depositio not a man, and you are a man’ the positum ) Dubitatio Sit Verum (5) proves Swyneshed’s first thesis, and (6) his second thesis. Conclusion Summary References

Obligations and Swyneshed’s Responsio Nova Disputations Stephen Read Swyneshed’s theory differs from Burley’s in several respects: Obligations ◮ First, Swyneshed, and the nova responsio in general, Disputations Walter Burley recognises only positio , impositio and depositio Obligational Disputations ◮ Next, Swyneshed makes a sharp distinction between the The Responsio Antiqua positio and the positum (and in general, between the Positio Burley’s thesis obligatio and the obligatum ) An Obligational Sophism ◮ Swyneshed also characterizes possible positio differently The Responsio Nova from Burley Roger Swyneshed Swyneshed’s Theses ◮ Most importantly, he characterizes “relevance” Swyneshed’s theory Other Types of differently Obligation Institutio ◮ Responses to irrelevant propositions need not be for the Petitio Depositio same instant, but only for the present Dubitatio Sit Verum ◮ Finally, he characterizes success and failure (winning Conclusion Summary and losing) differently. References

Obligations and Positio : The Responsio Nova Disputations Swyneshed’s rules for positio : Stephen Read ◮ The positum should be accepted only if it is contingent, that Obligations is, if responses to it outside the obligation would change as the Disputations Walter Burley facts change Obligational Disputations ◮ If a proposition follows from or is inconsistent with the The Responsio positum (regardless of what has been granted), it is said to be Antiqua Positio “relevant” ( pertinens ), otherwise “irrelevant” ( impertinens ) Burley’s thesis An Obligational ◮ if it is relevant, it is “obligated” and should be Sophism ◮ granted if it follows The Responsio ◮ denied if it is inconsistent Nova Roger Swyneshed ◮ if it’s irrelevant, it is not obligated and (given the casus and Swyneshed’s Theses Swyneshed’s theory how things are at that instant) should be Other Types of ◮ granted if (known to be) true, provided that is not inconsistent Obligation with the positio (the obligatio ) Institutio ◮ denied if (known to be) false, provided that is not inconsistent Petitio Depositio with the positio (the obligatio ), and Dubitatio ◮ doubted if it is not known whether it is true or false. Sit Verum Conclusion ◮ the obligation ends when either Summary ◮ the Respondent grants and denies the same proposition (unless References it is irrelevant), or ◮ when the Opponent says ‘ cedat tempus ’.

Obligations and Swyneshed’s answer to the problems with Disputations Burley’s theory Stephen Read ◮ Not every false proposition (compatible with the positum ) Obligations Disputations need be granted: Walter Burley ◮ the “tricks” ( cautelae ) introduced by Burley no longer work, Obligational Disputations since they only require the false proposition to be granted The Responsio because it follows from the positum in conjunction with a true Antiqua Positio irrelevant proposition which has been granted Burley’s thesis ◮ Responses change only when the facts change: An Obligational Sophism ◮ relevance is determined only by the positum and not by any The Responsio Nova irrelevant propositions subsequently proposed Roger Swyneshed ◮ Order does not affect responses: Swyneshed’s Theses Swyneshed’s theory ◮ again, since relevance only looks back to the positum , it cannot Other Types of depend on any subsequent responses or their order Obligation ◮ Possible positio need not lead to inconsistency: Institutio Petitio ◮ the pragmatic inconsistency introduced by posita such as Depositio Dubitatio ‘Nothing is posited to you’ is excluded by treating them as Sit Verum irrelevant and evaluating them as if the positio never was. Conclusion Summary References

Obligations and The Subsequent Reception Disputations Stephen Read Ashworth showed that each responsio had strong support in subsequent decades: Obligations Disputations Responsio Antiqua Responsio Nova Walter Burley Obligational Disputations Ralph Strode Robert Fland The Responsio Albert of Saxony Martinus Anglicus Antiqua Positio John Wyclif Burley’s thesis An Obligational Richard Brinkley anon., Tredecim questiones Sophism The Responsio William Buser Nova Marsilius of Inghen anon., Commentary on Marsilius Roger Swyneshed Swyneshed’s Theses John of Holland anon., Tres sunt modi Swyneshed’s theory Other Types of Peter of Mantua anon., Obligationes Obligation Peter of Candia secundum usum Oxonie Institutio Petitio Paul of Venice Richard Lavenham Depositio Dubitatio Sit Verum The majority of surviving treatises reject Swyneshed’s Conclusion innovation. But his ideas still influenced those who rejected Summary References it.

Obligations and Yrj¨ onsuuri’s Explanation Disputations ◮ How heretical is this logic? Can a conjunction be false even Stephen Read though both its conjuncts are true? Obligations ◮ No: that is to confuse granting with being true, denial with Disputations Walter Burley being false: Obligational Disputations ◮ A Respondent may be obliged to grant a proposition which is The Responsio false (e.g., the positum ) Antiqua ◮ He may be obliged to deny a proposition which is true (e.g., if Positio Burley’s thesis it is incompatible with the positum ) An Obligational Sophism ◮ He may even be obliged to doubt a proposition (i.e., to say ‘I The Responsio doubt it’) which he knows to be true or false Nova Roger Swyneshed ◮ Mikko Yrj¨ onsuuri suggested a book-keeping metaphor to Swyneshed’s Theses explain the logic involved Swyneshed’s theory Other Types of ◮ Catarina Dutilh Novaes formalized Yrj¨ onsuuri’s account. Let Obligation ◮ P + represent what is relevant and follows from the positum Institutio Petitio ( pertinens sequens ) Depositio ◮ P − represent what is relevant and inconsistent with the Dubitatio Sit Verum positum ( pertinens repugnans ) Conclusion ◮ I represent what is irrelevant ( impertinens ) Summary References

Obligations and Swyneshed’s Logic Disputations ◮ Then she sets out the tables for conjunction and disjunction as Stephen Read follows ( P + : pertinens sequens , P − : pertinens repugnans ): Obligations Disputations P + P + P + P − P − I φ n Walter Burley Obligational P + P − I P − I I φ m Disputations P + The Responsio P − I P − P − I φ n ∧ φ m Antiqua P + P + P + φ n ∨ φ m P − I I Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Logic Disputations ◮ Then she sets out the tables for conjunction and disjunction as Stephen Read follows ( P + : pertinens sequens , P − : pertinens repugnans ): Obligations Disputations P + P + P + P − P − I φ n Walter Burley Obligational P + P − I P − I I φ m Disputations P + The Responsio P − I P − P − I φ n ∧ φ m Antiqua P + P + P + φ n ∨ φ m P − I I Positio Burley’s thesis An Obligational ◮ Representing these as 3x3-matrices with some re-ordering, we Sophism The Responsio obtain Kleene’s strong matrices: Nova P + P + Roger Swyneshed ∧ I P − ∨ I P − Swyneshed’s Theses P + P + P + P + P + P + I P − Swyneshed’s theory P + Other Types of I I I P − I I I Obligation P + P − P − P − P − P − I P − Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Obligations and Swyneshed’s Logic Disputations ◮ Then she sets out the tables for conjunction and disjunction as Stephen Read follows ( P + : pertinens sequens , P − : pertinens repugnans ): Obligations Disputations P + P + P + P − P − I φ n Walter Burley Obligational P + P − I P − I I φ m Disputations P + The Responsio P − I P − P − I φ n ∧ φ m Antiqua P + P + P + φ n ∨ φ m P − I I Positio Burley’s thesis An Obligational ◮ Representing these as 3x3-matrices with some re-ordering, we Sophism The Responsio obtain Kleene’s strong matrices: Nova P + P + Roger Swyneshed ∧ I P − ∨ I P − Swyneshed’s Theses P + P + P + P + P + P + I P − Swyneshed’s theory P + Other Types of I I I P − I I I Obligation P + P − P − P − P − P − I P − Institutio Petitio ◮ Thus a conjunction can be irrelevant, and so denied (when Depositio Dubitatio known to be false), although its conjuncts are, respectively, Sit Verum pertinens sequens (so granted, though known to be false) and Conclusion Summary impertinens (irrelevant, so granted, since known to be true) References

Obligations and Swyneshed’s Logic Disputations ◮ Then she sets out the tables for conjunction and disjunction as Stephen Read follows ( P + : pertinens sequens , P − : pertinens repugnans ): Obligations Disputations P + P + P + P − P − I φ n Walter Burley Obligational P + P − I P − I I φ m Disputations P + The Responsio P − I P − P − I φ n ∧ φ m Antiqua P + P + P + φ n ∨ φ m P − I I Positio Burley’s thesis An Obligational ◮ Representing these as 3x3-matrices with some re-ordering, we Sophism The Responsio obtain Kleene’s strong matrices: Nova P + P + Roger Swyneshed ∧ I P − ∨ I P − Swyneshed’s Theses P + P + P + P + P + P + I P − Swyneshed’s theory P + Other Types of I I I P − I I I Obligation P + P − P − P − P − P − I P − Institutio Petitio ◮ Thus a conjunction can be irrelevant, and so denied (when Depositio Dubitatio known to be false), although its conjuncts are, respectively, Sit Verum pertinens sequens (so granted, though known to be false) and Conclusion Summary impertinens (irrelevant, so granted, since known to be true) References ◮ So Swyneshed’s logic is thoroughly orthodox, as are Kleene’s matrices.

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations 1. ‘You are A ’ ??? Walter Burley Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations 1. ‘You are A ’ ??? Walter Burley 2. Cedat tempus Obligational Disputations The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations 1. ‘You are A ’ ??? Walter Burley 2. Cedat tempus Obligational Disputations ◮ Either you are A or not: The Responsio Antiqua Positio Burley’s thesis An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations 1. ‘You are A ’ ??? Walter Burley 2. Cedat tempus Obligational Disputations ◮ Either you are A or not: The Responsio ◮ If you are A , ‘You are A ’ is true and irrelevant, so you should Antiqua grant it when under the obligation, and A signifies ‘ass’, so you Positio Burley’s thesis should grant that you are an ass An Obligational Sophism The Responsio Nova Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations 1. ‘You are A ’ ??? Walter Burley 2. Cedat tempus Obligational Disputations ◮ Either you are A or not: The Responsio ◮ If you are A , ‘You are A ’ is true and irrelevant, so you should Antiqua grant it when under the obligation, and A signifies ‘ass’, so you Positio Burley’s thesis should grant that you are an ass An Obligational ◮ If you are not A , ‘You are A ’ is false and irrelevant, so you Sophism should deny it when under the obligation, and A signifies ‘man’, The Responsio Nova so you should deny that you are a man Roger Swyneshed Swyneshed’s Theses Swyneshed’s theory Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References

Institutio (or Impositio ) Obligations and Disputations ◮ Let A signify ‘man’ in a false proposition, ‘ass’ in a true Stephen Read proposition and the disjunctive term ‘a man or not a man’ in a doubtful proposition: Obligations Disputations 1. ‘You are A ’ ??? Walter Burley 2. Cedat tempus Obligational Disputations ◮ Either you are A or not: The Responsio ◮ If you are A , ‘You are A ’ is true and irrelevant, so you should Antiqua grant it when under the obligation, and A signifies ‘ass’, so you Positio Burley’s thesis should grant that you are an ass An Obligational ◮ If you are not A , ‘You are A ’ is false and irrelevant, so you Sophism should deny it when under the obligation, and A signifies ‘man’, The Responsio Nova so you should deny that you are a man Roger Swyneshed ◮ If you doubt it, you doubt it when under the obligation, and A Swyneshed’s Theses signifies ‘man or not man’, so you doubt that you are a man or Swyneshed’s theory not. Other Types of Obligation Institutio Petitio Depositio Dubitatio Sit Verum Conclusion Summary References