Scholastic Logic Scholastic Logic: Chapter Two of Joseph Perrier's "The Revival of Scholastic Philosophy in the Nineteenth Century" (1909). (History) http://www.nd.edu/Departments/Maritain/etext/perrier2.html
Aristotle's Reform of Paideia Aristotle's Reform of Paideia: Article by Evelyn Barker, arguing that the principal aim of Aristotle's Organon was to reform the contemporary paedagogical role of dialectic. (History) http://www.bu.edu/wcp/Papers/Anci/AnciBark.htm
Medieval Theories of Modality Medieval Theories of Modality: Article at the Stanford Encyclopaedia of Philosophy. (History) http://plato.stanford.edu/entries/modality-medieval/
Syllogistic logic online Syllogistic logic online: This site contains an online program for studying Aristotle's syllogistic logic. The theory of Aristotle's ancient logic is also presented. (History) http://aristotelianlogic.glashoff.net
Scholasticism Scholasticism: Online text by Joseph Rickaby (1908). (History) http://www.nd.edu/Departments/Maritain/etext/scholas1.htm
Logic Logic: Entry in the Catholic Encyclopaedia (1917), dominated by a historical survey from Indian and Pre-Aristotelian philosophy to the Logic of John Stuart Mill. (History) http://www.newadvent.org/cathen/09324a.htm
Mediaeval Logic and Philosophy Mediaeval Logic and Philosophy: Resource maintained by Paul Vincent Spade at Indiana University. (History) http://pvspade.com/Logic/
Peter of Spain (Petrus Hispanus) Peter of Spain (Petrus Hispanus): Life and work of 13th century logician and author of the Tractatus; from the Stanford Encyclopedia by Joke Spruyt. (History) http://plato.stanford.edu/entries/peter-spain/
Square of Opposition Square of Opposition: Article in the Stanford Encyclopaedia of Philosophy, by Terence Parsons. (History) http://plato.stanford.edu/entries/square/
Medieval Theories of Analogy Medieval Theories of Analogy: Entry in the Stanford Encyclopaedia of Philosophy, by E. Jennifer Ashworth. (History) http://plato.stanford.edu/entries/analogy-medieval/
The Summulae of John Buridan The Summulae of John Buridan: A critical introduction by Gyula Klima. (History) http://www.fordham.edu/gsas/phil/klima/Intro.htm
On Dialectic On Dialectic: By St. Augustine. Latin original together with translation by J. Marchand. (History) http://www.georgetown.edu/faculty/jod/texts/dialecticatrans.html