Editing Syllogism (section)

==Early history==

{{Main|History of logic}}
In antiquity, two rival syllogistic theories existed: Aristotelian syllogism and Stoic syllogism.<ref name=":0">[[Michael Frede|Frede, Michael]]. 1975. "Stoic vs. Peripatetic Syllogistic." ''Archive for the History of Philosophy'' 56:99–124.</ref>

===Aristotle===
{{main|Term logic}}
[[Aristotle]] defines the syllogism as "a discourse in which certain (specific) things having been supposed, something different from the things supposed results of necessity because these things are so."<ref>[[Aristotle]], ''[[Prior Analytics]]'', 24b18–20</ref> Despite this very general definition, in ''[[Prior Analytics]]'' Aristotle limits himself to categorical syllogisms that consist of three [[categorical proposition]]s, including categorical [[modal logic|modal]] syllogisms.<ref>[[Susanne Bobzien|Bobzien, Susanne]]. [2006] 2020. "[http://plato.stanford.edu/entries/logic-ancient/ Ancient Logic]." ''[[Stanford Encyclopedia of Philosophy]]''. § [https://plato.stanford.edu/entries/logic-ancient/#Ari Aristotle].</ref>

The use of syllogisms as a tool for understanding can be dated back to the logical reasoning discussions of [[Aristotle]]. Before the mid-12th century, medieval logicians were only familiar with a portion of Aristotle's works, including such titles as ''[[Categories (Aristotle)|Categories]]'' and ''[[On Interpretation]]'', works that contributed heavily to the prevailing Old Logic, or ''[[logica vetus]]''. The onset of a New Logic, or ''[[logica nova]]'', arose alongside the reappearance of ''Prior Analytics'', the work in which Aristotle developed his theory of the syllogism.

''Prior Analytics'', upon rediscovery, was instantly regarded by logicians as "a closed and complete body of doctrine", leaving very little for thinkers of the day to debate, and reorganize. Aristotle's theory on the syllogism for ''[[assertoric]]'' sentences was considered especially remarkable, with only small systematic changes occurring to the concept over time. This theory of the syllogism would not enter the context of the more comprehensive logic of consequence until logic began to be reworked in general in the mid-14th century by the likes of [[John Buridan]].

Aristotle's ''Prior Analytics'' did not, however, incorporate such a comprehensive theory on the modal syllogism—a syllogism that has at least one [[Modal logic|modalized]] premise, that is, a premise containing the modal words ''necessarily'', ''possibly'', or ''contingently''. Aristotle's terminology in this aspect of his theory was deemed vague, and in many cases unclear, even contradicting some of his statements from ''On Interpretation''. His original assertions on this specific component of the theory were left up to a considerable amount of conversation, resulting in a wide array of solutions put forth by commentators of the day. The system for modal syllogisms laid forth by Aristotle would ultimately be deemed unfit for practical use, and would be replaced by new distinctions and new theories altogether.

=== Medieval syllogism ===

====Boethius====

[[Boethius]] (c. 475–526) contributed an effort to make the ancient Aristotelian logic more accessible. While his Latin translation of ''[[Prior Analytics]]'' went primarily unused before the 12th century, his textbooks on the categorical syllogism were central to expanding the syllogistic discussion. Rather than in any additions that he personally made to the field, Boethius' logical legacy lies in his effective transmission of prior theories to later logicians, as well as his clear and primarily accurate presentations of Aristotle's contributions.

====Peter Abelard====

Another of medieval logic's first contributors from the Latin West, [[Peter Abelard]] (1079–1142), gave his own thorough evaluation of the syllogism concept, and accompanying theory in the ''Dialectica''—a discussion of logic based on Boethius' commentaries and monographs. His perspective on syllogisms can be found in other works as well, such as ''Logica Ingredientibus''. With the help of Abelard's distinction between ''[[de dicto]]'' modal sentences and ''[[de re]]'' modal sentences, medieval logicians began to shape a more coherent concept of Aristotle's modal syllogism model.

====Jean Buridan====

The French philosopher [[Jean Buridan]] (c. 1300&nbsp;– 1361), whom some consider the foremost logician of the later Middle Ages, contributed two significant works: ''Treatise on Consequence'' and ''Summulae de Dialectica'', in which he discussed the concept of the syllogism, its components and distinctions, and ways to use the tool to expand its logical capability. For 200 years after Buridan's discussions, little was said about syllogistic logic. Historians of logic have assessed that the primary changes in the post-Middle Age era were changes in respect to the public's awareness of original sources, a lessening of appreciation for the logic's sophistication and complexity, and an increase in logical ignorance—so that logicians of the early 20th century came to view the whole system as ridiculous.<ref>{{cite encyclopedia|last=Lagerlund|first=Henrik|title=Medieval Theories of the Syllogism|url=http://plato.stanford.edu/archives/win2012/entries/medieval-syllogism/|encyclopedia=The Stanford Encyclopedia of Philosophy|date=2 February 2004 |publisher=Edward N. Zalta|access-date=17 February 2014}}</ref>