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[[Directory:Logic_Museum/The_Square_of_Opposition|Main]] (see also [[Directory:Logic Museum/The Square of Opposition|The Square of Opposition]]).

[[Directory:Logic_Museum/The_Square_of_Opposition|Main]] (see also [[Directory:Logic Museum/The Square of Opposition|The Square of Opposition]]).

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<div id="intro"><b>Introduction</b>

==Introduction==

The passages here represent early views (from approximately the 1230's to the 1260's) on the question of whether the <i>A</i> proposition 'a man is an animal' is true when no man exists. Authors include Sherwood and Kilwardby (who thought it is true when no man exists), and Bacon (who thought it isn't).   

The passages here represent early views (from approximately the 1230's to the 1260's) on the question of whether the <i>A</i> proposition 'a man is an animal' is true when no man exists. Authors include Sherwood and Kilwardby (who thought it is true when no man exists), and Bacon (who thought it isn't).   

I will try to locate the original sources where appropriate, and translate into English, where necessary.

I will try to locate the original sources where appropriate, and translate into English, where necessary.

<b>Richard the Sophister</b>

==Richard the Sophister==

Richard the Sophister (Richardus Sophista) was an English philosopher/logician who studied at Oxford, probably during the second quarter of the thirteenth century. Richard's identity is uncertain, but he is known to be the author of a collection of logically puzzling sentences, sometimes called “sophisms”, entitled <i>Abstractiones</i>. The Stanford Encyclopedia of Philosophy article has more [http://plato.stanford.edu/entries/richard-sophister here].   

[[Richard the Sophister]] (Richardus Sophista) was an English philosopher/logician who studied at [[Oxford University (Medieval)|Oxford]], probably during the second quarter of the thirteenth century. Richard's identity is uncertain, but he is known to be the author of a collection of logically puzzling sentences, sometimes called “sophisms”, entitled <i>Abstractiones</i>. The Stanford Encyclopedia of Philosophy article has more [http://plato.stanford.edu/entries/richard-sophister here].   

The passage here was probably written in the 1230's or 40's.  Richard argues that 'every man of necessity is an animal' has at least two senses, depending on the scope of 'of necessity'.  When it applies to 'every man', it says that every man is such that, by necessity, he is an animal, i.e. Plato is necessarily a man, Socrates is necessarily a man, &c.  In this sense it is false, because Socrates is not necessarily a man (he may possibly cease to exist).  When it applies to the whole sentence, i.e. when it says that the sentence 'every man is an animal' is necessarily true, the sentence is true.

The passage here was probably written in the 1230's or 40's.  Richard argues that 'every man of necessity is an animal' has at least two senses, depending on the scope of 'of necessity'.  When it applies to 'every man', it says that every man is such that, by necessity, he is an animal, i.e. Plato is necessarily a man, Socrates is necessarily a man, &c.  In this sense it is false, because Socrates is not necessarily a man (he may possibly cease to exist).  When it applies to the whole sentence, i.e. when it says that the sentence 'every man is an animal' is necessarily true, the sentence is true.

I have translated the Latin term <i>esse habitudinis</i> as 'conditional being'.  This is the being of the subject when a universal proposition (every man is an animal) is read as a conditional, i.e. 'if [anything] is a man, it is an animal'.  Kretzmann (in his translation of William of Sherwood below) renders it as 'relational being'.

I have translated the Latin term <i>esse habitudinis</i> as 'conditional being'.  This is the being of the subject when a universal proposition (every man is an animal) is read as a conditional, i.e. 'if [anything] is a man, it is an animal'.  Kretzmann (in his translation of William of Sherwood below) renders it as 'relational being'.

It is thought by some that Richard was actually Richard <i>Rufus</i>.  See [[http://rrp.stanford.edu/">The Richard Rufus of Cornwall project.

It is thought by some that Richard was actually [[Richard Rufus of Cornwall|Richard Rufus]].  See [http://rrp.stanford.edu The Richard Rufus of Cornwall project].

<b> Robert Kilwardby </b>]]

==Robert Kilwardby==

Robert Kilwardby (c 1215 – 1279) composed a number of works on logic and theology.  He was a student in Paris in the 1230's.  He is mainly known for his role in the Oxford condemnations of March 1277, following Tempier's condemnation in Paris.  Kilwardby prohibited thirty propositions, fourteen concerning grammar and logic, the rest concerning natural philosophy.  According to Broadie, among these were those claiming that a necessary truth requires the perpetual existence of its subject (allegedly false, because God's knowledge of contingent truths is itself necessarily true), and that only what exists can be the subject of a demonstration (allegedly false, because it is possible to formulate a demonstration about a non-existent essence).

[[Robert Kilwardby]] (c 1215 – 1279) composed a number of works on logic and theology.  He was a student in Paris in the 1230's.  He is mainly known for his role in the [[Directory:Logic Museum/Oxford condemnations of 1277|Oxford condemnations of March 1277]], following Tempier's condemnation in Paris.  Kilwardby prohibited thirty propositions, fourteen concerning grammar and logic, the rest concerning natural philosophy.  According to Broadie, among these were those claiming that a necessary truth requires the perpetual existence of its subject (allegedly false, because God's knowledge of contingent truths is itself necessarily true), and that only what exists can be the subject of a demonstration (allegedly false, because it is possible to formulate a demonstration about a non-existent essence).

The quotations here, probably written around 1250, are taken from a secondary source (Henry <i>loc. cit.</i>), who took them from Ebbesen.  They are not definitely attributable to Kilwardby, but are certainly consistent with his position.  The author argues that 'a man is an animal' is true even when no man exists, because, just as in reality someone being a man is related to his being an animal, in the same way the thought (<i>intellectus</i>) of his being a man is related to the thought of his being an animal.  Therefore 'a man is an animal' is true in virtue of the thought, rather than the reality, and therefore it is true even though no man exists.  (Just as we now say that a proposition is analytically true, or that it represents a necesary relation between concepts, though Kilwardby would not have expressed himself in this way).

The quotations here, probably written around 1250, are taken from a secondary source (Henry <i>loc. cit.</i>), who took them from Ebbesen.  They are not definitely attributable to Kilwardby, but are certainly consistent with his position.  The author argues that 'a man is an animal' is true even when no man exists, because, just as in reality someone being a man is related to his being an animal, in the same way the thought (<i>intellectus</i>) of his being a man is related to the thought of his being an animal.  Therefore 'a man is an animal' is true in virtue of the thought, rather than the reality, and therefore it is true even though no man exists.  (Just as we now say that a proposition is analytically true, or that it represents a necesary relation between concepts, though Kilwardby would not have expressed himself in this way).

This was a reasoning used by later philosophers to explain why 'essential propositions' must be eternally and necessarily true.  A counter-argument, given by Boethius of Dacia [link to follow], was that 'composition in the understanding' (such as the composition of the concepts <i>man</i> and <i>animal</i> in the thought <i>man is an animal</i>) is only true because there is composition in reality.  The thought that a man is an animal, is only true if some real man is an animal.  Thus 'a man is an animal' is false when no man exists, because there is no corresponding composition in reality.  [<b>link to follow</b>].

This was a reasoning used by later philosophers to explain why 'essential propositions' must be eternally and necessarily true.  A counter-argument, given by Boethius of Dacia [link to follow], was that 'composition in the understanding' (such as the composition of the concepts <i>man</i> and <i>animal</i> in the thought <i>man is an animal</i>) is only true because there is composition in reality.  The thought that a man is an animal, is only true if some real man is an animal.  Thus 'a man is an animal' is false when no man exists, because there is no corresponding composition in reality.  [<b>link to follow</b>].

<b>Anon</b>

==Anon==

The anonymous quotations are from a manuscript <i>Omnis homo de necessitate est animal</i>, ms. Paris, <i>Nat. lat.</i> 16135, fol. 11rb-12vb, written c. 1250.  My source was [[Directory:Logic Museum/Alain de Libera|De Libera]] 1991.  The author mentions the fact that there is disagreement about whether the proposition is true when no men exist, and also mentions the distinction between essential being (as in 'a dragon is fire breathing') and actual being (a fox is in the garden).   

The anonymous quotations are from a manuscript <i>Omnis homo de necessitate est animal</i>, ms. Paris, <i>Nat. lat.</i> 16135, fol. 11rb-12vb, written c. 1250.  My source was [[Directory:Logic Museum/Alain de Libera|De Libera]] 1991.  The author mentions the fact that there is disagreement about whether the proposition is true when no men exist, and also mentions the distinction between essential being (as in 'a dragon is fire breathing') and actual being (a fox is in the garden).   

It also mentions the idea of <i>esse habituale</i> - conditional or relational being.  'Every dragon breathes flame' is true in the sense that it predicates conditional being – <i>if</i> any dragon exists, <i>then</i> it breathes flame, which is true whether or not a dragon exists.  A corollary of this view is the distinction between the use of 'is' as an absolute predicate (e.g. 'Caesar is', i.e. Caesar exists), and its use as a mere copula, as in 'Caesar is a man'.

It also mentions the idea of <i>esse habituale</i> - conditional or relational being.  'Every dragon breathes flame' is true in the sense that it predicates conditional being – <i>if</i> any dragon exists, <i>then</i> it breathes flame, which is true whether or not a dragon exists.  A corollary of this view is the distinction between the use of 'is' as an absolute predicate (e.g. 'Caesar is', i.e. Caesar exists), and its use as a mere copula, as in 'Caesar is a man'.

<b>William of Sherwood</b>]]

==William of Sherwood==

William of Sherwood (c. 1200-66)was a master at Oxford in 1252, and is known mostly for two works on logic, the <i>Introduction to Logic</i> (c. 1250) and the <i>Syncategoremata</i> (c. 1250).  The two passages here are taken from these.  Sherwood argues that 'every man is an animal' has two senses, sometimes meaning things that actually exist, in which case it is false when no man exists, sometimes meaning that a certain nature (being an animal) is suited naturally to be in a certain kind of thing (man), even though it is not actually in one.  In the latter sense, it has the force of the conditional 'if a man is [i.e. exists], an animal is', and thus is true even when no man exists.

[[William of Sherwood]] (c. 1200-66)was a master at Oxford in 1252, and is known mostly for two works on logic, the <i>Introduction to Logic</i> (c. 1250) and the <i>Syncategoremata</i> (c. 1250).  The two passages here are taken from these.  Sherwood argues that 'every man is an animal' has two senses, sometimes meaning things that actually exist, in which case it is false when no man exists, sometimes meaning that a certain nature (being an animal) is suited naturally to be in a certain kind of thing (man), even though it is not actually in one.  In the latter sense, it has the force of the conditional 'if a man is [i.e. exists], an animal is', and thus is true even when no man exists.

He is explicit that a term can 'supposit for' (roughly: denote)something that does not exist – e.g., if there are only two men 'every man exists' is false (based on the bizarre idea that if there are only two men 'every man exists' is false, in which case its contradictory, 'some man does not exist' is true).  Therefore a man does not exist.  But nonexistence is not predicated of something that exists; therefore 'man' supposits for something that does not exist.

He is explicit that a term can 'supposit for' (roughly: denote)something that does not exist – e.g., if there are only two men 'every man exists' is false (based on the bizarre idea that if there are only two men 'every man exists' is false, in which case its contradictory, 'some man does not exist' is true).  Therefore a man does not exist.  But nonexistence is not predicated of something that exists; therefore 'man' supposits for something that does not exist.

It seems to be the view roundly criticised in Ockham's <i>Summa Logicae</i> II.4 (also to appear in the Logic Museum – <b>link to follow</b>), although Ockham's attack may also be aimed at Richard the Sophister.

It seems to be the view roundly criticised in [[William of Ockham]]'s <i>Summa Logicae</i> II.4 (also to appear in the Logic Museum – <b>link to follow</b>), although Ockham's attack may also be aimed at Richard the Sophister.

<b>Roger Bacon</b>

==Roger Bacon==

Roger Bacon (c 1214 – post 1292) is an important figure of the thirteenth century.  He was at Oxford in the 1230's, at Paris in the 1240's, later returning to Oxford where he remained until the 1290's.  He is thought to have anticipated and possibly influenced the nominalistic positions taken up later by Scotus and Ockham [<b>link to follow</b>].

[[Roger Bacon]] (c 1214 – post 1292) is an important figure of the thirteenth century.  He was at Oxford in the 1230's, at Paris in the 1240's, later returning to Oxford where he remained until the 1290's.  He is thought to have anticipated and possibly influenced the nominalistic positions taken up later by Scotus and Ockham [<b>link to follow</b>].

The passage here is quoted in Henry (p. 265) who has taken it from a secondary source (Ebbesen & Pinborg – see [[nullohomine.htm">bibliography).  It is probably from the the <i>Summulae Dialectices</i>, which De Libera thinks was written at Oxford around the 1250's.  This is a mature work, which contains two important doctrines: the doctrine of univocal appellation, and the doctrine of predication in respect of empty terms.  Bacon argues that a word cannot apply univocally (i.e. in the same sense) to an existing and a non-existing thing.  This doctrine is also found in his later works.   

The passage here is quoted in Henry (p. 265) who has taken it from a secondary source (Ebbesen & Pinborg – see [[nullohomine.htm">bibliography).  It is probably from the the <i>Summulae Dialectices</i>, which De Libera thinks was written at Oxford around the 1250's.  This is a mature work, which contains two important doctrines: the doctrine of univocal appellation, and the doctrine of predication in respect of empty terms.  Bacon argues that a word cannot apply univocally (i.e. in the same sense) to an existing and a non-existing thing.  This doctrine is also found in his later works.   

Thus Bacon rejects the predication of empty terms, and thus rejects propositions 'every man of necessity is an animal, with no men existing' (<i>Omnis homo de necessitate est animal, homine non existente</i>) and <i>Caesar est homo, Caesare mortuo</i> (Caesar is a man, with Caesar dead).  Hackett says that Bacon's position was condemned by Robert Kilwardby in the Oxford condemnations of March 1277.   

Thus Bacon rejects the predication of empty terms, and thus rejects propositions 'every man of necessity is an animal, with no men existing' (<i>Omnis homo de necessitate est animal, homine non existente</i>) and <i>Caesar est homo, Caesare mortuo</i> (Caesar is a man, with Caesar dead).  Hackett says that Bacon's position was condemned by Robert Kilwardby in the Oxford condemnations of March 1277.   

<b>References</b>]]

==References==

*[[Directory:Logic Museum/H.A.G. Braakhuis|Braakhuis, H.A.G]]. in 'Kilwardby versus Bacon? The Contribution to the Discussion on Univocal Signification of Beings and Non-Beings Found in a Sophisma attributed to Rober Kilwardby', in <i>Medieval Semantics and Metaphysics. Studies dedicated to L.M. De Rijk, PhD on the Occasion of his 60th birthday</i>, ed. E.P. Bos, (Artistarium, Supplementa 2), Nijmegen, Ingenium Publishers, 1985, 126-142 [extracts].]]

*[[Directory:Logic Museum/H.A.G. Braakhuis|Braakhuis, H.A.G]]. in 'Kilwardby versus Bacon? The Contribution to the Discussion on Univocal Signification of Beings and Non-Beings Found in a Sophisma attributed to Rober Kilwardby', in <i>Medieval Semantics and Metaphysics. Studies dedicated to L.M. De Rijk, PhD on the Occasion of his 60th birthday</i>, ed. E.P. Bos, (Artistarium, Supplementa 2), Nijmegen, Ingenium Publishers, 1985, 126-142 [extracts].]]

==Notes==

==Notes==

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[[Category:Logic Museum Parallel Texts]]

[[Category:Logic Museum Parallel Texts]]