Welcome to The Logic Museum, a site devoted to the history of Logic up to and including the period of Frege and Russell. "Traditional Logic" has a long history, and is much richer than implied by standard treatments of the subject (usually limited to a cursory discussion of the syllogistic moods, and of the awful 'square of opposition'). The site is still under construction, but includes online texts not available elsewhere, links to other history of logic sites, and a discussion page.

Subjects in logic and metaphysics
Primary sources in logic and metaphysics (Logic Museum II)
Latin site searcher Search for a Latin word or phrase in a way that doesn't get mixed up with "English latin" words (e.g,. ratio).

15 May 2011. Augustine On Lying, and now the whole of the Confessions.

2 May 2011. The first part of Anselm's Proslogion. Gaunilo's objection and Anselm's reply to the objection, to follow soon.

1 May 2011. A new sortable index of the main texts in the Logic Museum.

30 April 2011. St Anselm's Monologion

15 April 2011. Book I question I of the Summa on its own. This is part of a test to understand why Google does not index certain pages, together with a modified translation (in case Google is ignoring it because on other sites).

11 April 2011. A new translation of chapters 5-9 of Book I of the the Summa Logicae.

26 March 2011. Here it is: the first few chapters of Ockham's monumental work, the Summa Logicae, in a new translation for the internet. Plus some other translations that have been lying around here for ages - the index is here.

19 March 2011. It's a nice Spring day. Here is a new translation of Horace Ode 7, book 4.

19 February 2011. New translation: Question 4 of Walter Burley's 1301 Questions on the Perihermenias.

19 February 2011. The big one: Thomas' commentary on Book VII of Aristotle's Metaphysics. As with all the commentaries here, it is closely linked to Aristotle's text. In this case, William of Moerbeck's Latin translation from the Greek, in parallel with Ross's English translation from the Greek. The text also includes links to Averroes' commentary on the Metaphysics, in the Latin that translated from the Arabic (from an edition published in Venice in 1562), also links to a 14th century manuscript of William's translation.

Book VII is at the heart of the Metaphysics. It is very difficult to understand. Thomas's commentary is usually very clear, and helps a bit.

5 February 2011. De Potentia Dei by Thomas.

30 January 2011. And the whole of the third part. [---], beginning at [III 1-6].

29 January 2011. The whole of the second part of the second book of Summa Theologiae has now been uploaded.

23 January 2011. Happy New Year to all Museum readers! A big addition I have been working on all month: Aristotle's Physics, linked with Bekker numbers, like (most of) the other Aristotle here, and unlike any other versions on the web. And to go with it, Thomas Aquinas' excellent commentary. Each is linked to the other, so there is none of that dreadful page turning thing, or looking in indexes. I can't tell you how much work this was.

28 December 2010. Aquinas commentary on the Posterior Analytics. Includes links to an English version of the Analytics, translated by G. R. G. Mure. As promised, these English versions will eventually be replaced by parallel Latin-English versions.

2 December 2010. Aquinas commentary on Metaphysics V and Metaphysics VI now out.

2 December 2010. Boethius' De Hebdomadibus.

25 November 2010. The second of the second now available. Questions 1-7 on the object of faith; the virtue of faith; the cause and effects of faith; questions 8 and 9 on understanding and knowledge, and questions questions 10-15 on unbelief, heresy, apostasy and blasphemy.

21 November 2010. Aquinas commentary on Aristotle's Perihermenias is now available. Includes links back to the Aristotle in Latin-English.

9 November 2010. Questions 106-108 and Questions 109-114 of the first part of the second book of Summa Theologiae. On the new law, and grace. And that concludes Prima Secundae. Next (but not today) we start on Secunda Secundae.

29 October 2010. Questions 98-105 of the first part of the second book of Summa Theologiae. On the old law.

29 October 2010. Is every man an animal when no man exists? Helping the Google crawler out, as it seems to have forgotten this page.

25 October 2010. questions 93-97 of the first part of the second book of Summa Theologiae.

22 October 2010. Thomas Aquinas' commentary on Aristotle's Metaphysics, book IV is here. The index and introduction is here.
And questions 90-92 of the first part of the second book of Summa Theologiae.

16 October 2010. Questions 71-89 of the first part of the second book of Summa Theologiae. On vice and sin: index is here.

16 October 2010. Thomas Aquinas' commentary on Aristotle's Metaphysics, third book is here. The index and introduction is here.

13 October 2010. Thomas Aquinas' commentary on Aristotle's Metaphysics, second book is here.

12 October 2010. Thomas Aquinas commentary on Aristotle's Metaphysics. First book now available here. The index and introduction is here.

10 October 2010. Questions 49-70 of the first part of the second book of Summa Theologiae. Concerning habits in general, their causes and effects; the virtues - intellectual, moral, cardinal and theological; the gifts, beatitudes and blessings of the Holy Ghost.

9 October 2010. Questions 22-48 of the first part of the second book of Summa Theologiae now uploaded. Also, a short work 'On arguments for the faith' directed against Muslims.

29 September 2010. Questions 1-21 of the first part of the second book of Summa Theologiae. This is part of a continuing project to take the whole work (three books) into a parallel Latin-English version (the only one on the web). There is now full indexing on the questions for Book II. For example, if you want to link to q. 19 a. 8 arg. 1, use the link as follows: authors/aquinas/summa/Summa-IIa-18-21.htm#q19a8arg1. More to come.

29 September 2010. An addition to the section on the Ontological argument. Two chapters from Phillips. Generally good value, and a characterisation of the argument that would be hard to find anywhere else on the Web.

26 September 2010. Welcome to the new Logic Museum in its splendid new dedicated website! A large addition today: a page on individuation. Under construction, eventually it will contain all the key scholastic texts, from Aristotle and Boethius to Suarez, on the difficult subject of individuation. First off, Boethius' On the Trinity, and Aquinas' unfinished commentary on it. Plus a number of other works by Thomas on the same subject.

25 October 2009. Google pages have deleted Logic Museum II and moved it to another site which does not provide such a good service. Consequently I have moved most of the material to Greg Kohs excellent WikiBiz wiki here. Some of the material has still to be moved over. However, the whole of Book I of the Summa is now there, including some questions that I forgot to include on the original site. Note the new site contains much extra information thanks to the wiki format. For example a list of medievalists here, and a growing catalogue of medieval philosophers. The main page is here

1 March 2009. Priscian's Institutiones Grammaticae now available (Latin version only) in the Logic Museum annex. I had ignored Priscian before, thinking of him as a grammarian. Which he is, mostly, but there are interesting philosophical and logical insights in this enormous work. Such as that the present time is that of which part is past, part is future (Book 8, p. 414). Scotus uses this to explain how a sentence in the present tense (e.g. "Robert is just passing through the door") may be true even when the event it refers to may just be over. 'praesens tempus est cuius pars praeteriit, parsque futura est'

7 February 2009. A link to my article about Andrew of Cornwall here in an attempt to discover why Google seems consistently to favour Wikipedia. I created a smaller version of the same article in Wikipedia (which I will not link to for obvious reasons), but Google sadly ignores it. Please note the developments at the new Logic Museum at MWB, which will eventually supersede this site.

June 21 2008. Cicero's commentary on Aristotle's Topics in the Logic Museum here.

June 14 2008. Questions 106-110, Questions 111-114, and Questions 115-119 now available. This brings us to the end of the First Part of the work. Only Part II, I and II, and Part III to go. This is the only parallel Latin-English version on the Internet. Also the only complete one. There are a number of missing bits of the internet versions currently available.

June 7 2008. Questions 103-105 of the Summa now here.

May 28 2008. Questions 94-102 of the Summa now available here.

May 11 2008. Another part (questions 90-93) of Aquinas' Summa Theologiae, here. I am sorry it has been a bit quiet at the museum lately. This is because of the work mentioned below on the Scotus. Having checked all the Latin of Andrews' and Noone's excellent critical edition of 2004 (and thanks to Tim Noone for fielding some tricky questions on the text) I am now translating the rest. Up to Question 9 of the first version. My ban from Wikipedia is now over, and I am back as Peter Damian. I tidied up the article on Medieval Philosophy (although this has some way to go) added some bits and pieces such as the Isagoge, and also worked on Duns Scotus.

April 13 2008. Caesar's Gallic Wars now available. No, not logic, I agree. I am working on a full translation of Scotus' commentary on the Perihermenias and this was just light relief. The Scotus may end up in a proper paper translation that you have to buy, or find in a library. I'm still thinking about that one. Personally I prefer the idea of source material that is available to everyone, on the net, but reputations are built on paper, at the moment.

March 15 2008. Here are the contents of Radulphus Brito's book on the Old Logic (Porphyry's Isagoge, the Categories and On Interpretation). It includes links to the digital version - very readable - of an edition by Johannes Rubeus Vercellensis and Albertinus Vercellensis, Venice, published about 1499. The title page reads 'Magistri Rodulphus Britonis super arte veteri'.

March 1 2008. More virginal internet-Latin, with translation. This is Simon of Faversham asking whether Caesar is dead. Yes.

February 24 2008. Some more Latin new to the internet (and I believe never in an critical edition), Two questions on the Perihermenias by early fourteenth century logician Radulphus Brito. With English translation, of course.

February 16 2008. Happy New Year, belatedly. A new translation of a question by Boethius of Dacia: is every man of necessity an animal? No. Part of a new section on late thirteenth century and modist writing on the topic of the A proposition, and its truth value when its subject does not exist. Also, another modist piece, two questions on Aristotle's Metaphysics, by Siger of Brabant.

December 1 2007. Questions 44-49 of the Summa here. A medieval Advent hymn here. Sorry about the site collapsing yesterday. BT limit the traffic and there must have been a 'burst'. Not sure which page it was. Also questions 84-89 now split up into separate files: 84-86 and 87-89. This was a large set of files, and Google can't cope with that.

November 24 2007. An updated version of Moerbeke's translation of the Metaphysics. Now contains links to Averroe's commentary on the Metaphysics at Gallica.

November 21 2007. Final part of the New Organon (Bk II, 38-52) is here. Also questions 39-43 of the Summa.

November 17 2007. A useful guide to conjunctions in Latin is new to the net here. Handy for those who have difficulty in sorting out their itaque's from the igitur's. And what exactly is the difference between vero and autem? This contains everything you need to know.

November 8 2007. Linking again to 84-89 of the Summa. Exactly what drives Google is a mystery.

November 3 2007. The rest of Book I of New Organon (aphorisms 68-130) now in the annex here.

October 28 2007. Francis Bacon's New Organon (preface and aphorisms 1 - 68), in Logic Museum II.

October 17 2007. On the City of God, in parallel Latin-English, now here in Logic Museum II.

October 13 2007. Essence and Existence by Thomas Aquinas is here.

October 9 2007. More pages from the Summa Theologiae of St Thomas Aquinas. Index is in the Logic Museum annex here.

October 7 2007. William Moerbeke's translation of the Aristotle's Metaphysics is here. First time for the Latin text on the internet. I have linked it to the corresponding pages in a beautiful fourteenth century manuscript of the same translation. Also there is Aquinas’ commentary on the same chapter (Latin only, for the time being).

September 30 2007. Logic Museum annex is here.

September 22 2007. Some more links to manuscript pages, including images of Peter of Spain's text on logic, and Zabarella's 850 page logical works.

September 22 2007. Update to the manuscript guide (Petrus Hispanus at the bottom). And a link to Dana Sutton's splendid online bibliography of neo-Latin texts here.

August 31 2007. Linking to two pages as an experiment, in an annex to the Logic Museum on GooglePages. This will be for large parallel texts for which there is no room in the main 'building' of the Logic Museum. Begining with Abelard's splendid story of his troubles and with questions 84-89 of Volume I of the Summa Theologiae. I would put more here but for some bizarre reason Google don't allow subdirectories or anything like that.

Song for Athene.

Alleluia. May flights of angels sing thee to thy rest.
Alleluia. Remember me O Lord, when you come into your kingdom.
Alleluia. Give rest O Lord to your hand-maid, who has fallen asleep.
Alleluia. The Choir of Saints have found the well-spring of life, and door of paradise.
Alleluia. Life: a shadow and a dream.
Alleluia. Weeping at the grave creates the song. Alleluia.
Alleluia. Come, enjoy rewards and crowns I have prepared for you.

August 18 2007. More material on 'every man is an animal'. The passages here represent early views (from approximately the 1230's to the 1260's) on the question of whether the A 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).

July 27 2007. A new part of the Logic Museum on the history of logical form. It begins with two new translations of Ockham, one from the Summa Logicae, the other from his commentary on Aristotle's Perihermaneias. These are concerned with the idea of a 'mental language', a language which exists in the mind (or 'in the soul') consisting of conceived terms, propositions constructed from them, corresponding to and signified by our ordinary outward language of written and spoken terms. The notion of a mental language, or language of thought, is closely connected with the idea of logical form. The new page also includes Wittgenstein's 1931 paper 'On Logical Form'.

July 20 2007. A new page on the ontological argument. Starting off with Aristotle's proof of the existence of God, from the Metaphysics, and Descartes' argument, from the Meditations.

And here is a bit from the 1911 Britannica article on the syllogism, which is an addition to the page on the hypothetical syllogism.

July 14 2007. A new page of references on the vexing question of whether 'every man is an animal' is true when no man exists? According to Parsons, for most of the history of Aristotelian logic, logicians assumed that negative particular propositions are vacuously true if their subjects are empty, ergo they must have thought that universal affirmative propositions are vacuously false if their subjects are empty, ergo they thought 'every man is an animal' is false when there are no men. So did they think that? It turns out some of them did, but most of them didn't. The page above contains references to the primary sources on this question, most of them obscure enough to merit inclusion in the Logic Museum. In the next few months I will post some of them, with my own translations.

June 23 2007. Some more pages in the hypothetical syllogism: from the eighteenth century, George Campbell argues that the syllogism involves a petitio principii. And from the nineteenth century John Stuart Mill argues the same thing.

Still to follow, I know, are the translations of commentaries of the Perihermaneias. But I just found a commentary (actually questions) by Scotus that I never knew existed. As these have a bearing on my dispute with Parsons about the O proposition of the Square, I am now translating this. So, another few weeks I expect.

In addition, more links to manuscript pages, including the Scotus text mentioned above.

June 8 2007. Back from the conference at Montreux where my paper was well received. Hanach Ben-Yami presented a good paper which inspired me to set up a page on the hypothetical syllogism. This has a link to his paper. Best wishes to any of those I met who are reading this! And congratulations to Jean-Yves Beziau on organising this successful event.

May 12 2007. A new page on reference, under construction. First articles, Buridan on the expository syllogism, and Dear Russell, Dear Frege.

May 7 2007. Some new material this month – much Square-of-Opposition material. First, Apuleius' commentary on the Perihermaneias. A very early commentary, and possibly the first to include the famous diagram of the square. The text is linked to an early manuscript, held in the Schoenberg collection. Next, my own translation of chapters 6 and 7. This is from the Latin, not the Greek, intended as a basis for translations of the medieval commentaries on those chapters. Finally, a paper by J.P.N. Land which appeared in Mind 1876, a critique of what is now know as the Brentano-Venn interpretation of universal and existential propositions. Sometimes wrongly called the Boolean interpretation.

April 24th 2007. Linking to another test page.

The translation of Distinction III of Book II of Bonaventura's Commentary on the sentences is finally ready. See what's new at the Franciscan Archive for details. Or just go to the page for Book Two.

Currently I am finishing off the translation of Aquinas' Commentary on the Perihermaneias, followed by a part of Abelard's Dialectica which corresponds to the same.

April 15th 2007. Linking to manuscripts (copy) this time.

March 29 2007. Linking to manuscripts again, which Google did not pick up earlier.

News. It has been a bit quiet in the Museum recently, but that's because there is a lot of work behind the scenes. I am finishing off a translation of Distinction III of Bonaventura's Commentary on the Sentences . Also my paper for the Montreux International Congress on the Square of Opposition has been accepted (should be an interesting event with Kripke, Wollenski and Parsons all speaking), and there are some extra pages I need to prepare for the Museum that are connected with this. This will include a new translation of chapters 6 and 7 of the Perihermaneias. There is a translation in the Museum of the whole work, but this is a third-party translation (by Edghill), which is moreover a translation of Aristotle's Greek, and not of Boethius' Latin translation of the Greek. The translation I am working on is intended to follow the Latin closely, to give us a better idea of what medieval logicians thought Aristotle was talking about (as opposed to what he was actually talking about, in Greek).

The Montreux paper itself is a critique of the position argued for by Terence Parsons in the SEP article here

Further work in progress: translations of Boethius two commentaries on the Perihermaneias, chapters 6 and 7 again. And similarly for Aquinas and Abelard's commentaries. These should be ready for Montreux in June. Also, I have updated the Wikipedia entry on the Square of Opposition

March 9 2007. Linking to a new blog, covering the changes to admissions policy at Lady Margaret School Fulham, which amount to a blatant attack on the concept of faith schools.

December 16 2006. Hits on this main page now rising to 1,000 a month. That's good news. The bad news is that the count for the pages underneath aren't going up. Thus, something is driving a lot of people here, and immediately something is driving them away. Because it's in fact a site about medieval logic, and, well, rather dull? Do send me an email (d3uckner AT Let me know how you got here, what you expected to see, and whether you were disappointed with what you found. If you liked, it, what else what you like to see? Could the navigation be better? All that sort of customer relation management thing.

Another addition today is Herve Natalis on equipollence. It is a translation (possibly the first translation into English) of part of the Summa Totius Logicae thought for a long time to have been written by Aquinas, now thought to have been written by Hervé of Nedeilec (Hervaeus Natalis), who died in 1323.

December 8 2006. And the paper (on the square of opposition) is nearly finished. More than that, there has been a lot of development going on in the Museum, namely a whole new wing, dedicated to manuscripts. Lots of stuff will be going in there, including Aristotle's metaphysics, Boethius' and Apuleius' commentaries on the Perihermaneias, but these are not ready yet. What is ready includes a sample of the 1493 edition of Bonaventura's Commentary on the Sentences. A page from the a late 9th century copy of the Vulgate, first chapter of Mark (this is the one with an improbable family tree of Jesus, tracing his ancestry from King David to Joseph, then strangely continuing with the proposition that Joseph was not Jesus' father after all. Another page from the same manuscript, chapters I and II of Luke, including the (currently) seasonal topic of the Annunciation. This has both English and Latin: click on the text itself to move between the two.

October 30 2006. The paper improves gradually. In the meantime, for amusement, I include the function above. This allows you to search for Latin phrases on those websites which have Latin texts. Please send me the URLs of any sites (medieval or classical) that would be suitable to include in this. Some of the sites have parallel English texts.

September 30 2006. A short break in Italy on holiday, so no time to work on the museum. In any case, I am struggling with a paper on the Square of Opposition, and there is no time for the internet. However, here is a digital version of W.M.Thorburn's 1918 paper The Myth of Ockham's Razor. This is a good one. Interestingly it proved that the eccentric and generally barking mad Wikipedia can sometimes get things right. Sometimes, anyway.

July 19 2006. A new page on truth. Includes Question 16 (Book I.I) of the Summa Theologiae, Chapter II of Joachim's The Nature of Truth.

July 18 2006. A new piece in the eternity section. A piece from 1959 by A.N.Prior, Thank Goodness That's Over.
An entire new section under development is the Square of Opposition, despite the promise above that the Museum would never contain anything of the sort. In fact, there are interesting things to be said about the Square, and particularly there is much primary material, including Boethius translation of Aristotle's Perihermaneias, Apuleius' commentary, Boethius commentary, and other material by Abelard, Aquinas, and Buridan. Much of this has never been translated into English, so my tattered copy of Dr Smith, and of Lewis, has never been so busy. Still under development.

July 1 2006. Finally the new exhibition room on connotation is ready, though not all exhibits were ready in time for the opening. A wide range of material from Aristotle to Frege, a guest contributor (Francesco Franco) and fresh translations, appearing for the first time on the world wide web, of two pieces by the wonderful William Ockham.

May 10 2006. Lots more. McTaggart on the unreality of time (the A and B series one). The argument in Augustine's City of God about the footprint. Plus some other things, all to be found here.

May 1 2006.

A parallel text of Aquinas' De Eternitate Mundi is here. Temporary only, I will replace it with my own translation and introduction when time allows.

April 28 2006.

A couple of new things. A books page here, and here is the Prologue from S. Bonaventura's second book on Peter Lombard's sentences, published in 1493 by Kilian Fischer, in parallel with the Latin text from a more modern edition. Took about five days to prepare, as it was all in images. What a nightmare. I shall stick to word processing from now on.

Nick's web site.

THE LOGIC MUSEUM Copyright © E.D.Buckner 2009