Editing History of logic (section)

===The textbook tradition===
[[File:Fennerartoflogic-small.jpg|alt=Frontispiece, with title beginning "The Artes of Logike and Rethorike, plainlie set foorth in the English tounge, easie to be learned and practised".|thumb|[[Dudley Fenner]]'s ''Art of Logic'' (1584)]]
''Traditional logic'' generally means the textbook tradition that begins with [[Antoine Arnauld]]'s and [[Pierre Nicole]]'s ''Logic, or the Art of Thinking'', better known as the ''[[Port-Royal Logic]]''.<ref>''Oxford Companion'' p. 504, article "Traditional logic"</ref> Published in 1662, it was the most influential work on logic after Aristotle until the nineteenth century.<ref name="Buroker xxiii">Buroker xxiii</ref> The book presents a loosely Cartesian doctrine (that the proposition is a combining of ideas rather than terms, for example) within a framework that is broadly derived from Aristotelian and medieval [[term logic]]. Between 1664 and 1700, there were eight editions, and the book had considerable influence after that.<ref name="Buroker xxiii"/> The Port-Royal introduces the concepts of [[extension (semantics)|extension]] and [[intension]]. The account of [[proposition]]s that [[John Locke|Locke]] gives in the ''Essay'' is essentially that of the Port-Royal: "Verbal propositions, which are words, [are] the signs of our ideas, put together or separated in affirmative or negative sentences. So that proposition consists in the putting together or separating these signs, according as the things which they stand for agree or disagree."<ref>(Locke, ''An Essay Concerning Human Understanding'', IV. 5. 6)</ref>

[[Dudley Fenner]] helped popularize [[Ramist]] logic, a reaction against Aristotle. Another influential work was the ''[[Novum Organum]]'' by [[Francis Bacon]], published in 1620. The title translates as "new instrument". This is a reference to [[Aristotle]]'s work known as the ''[[Organon]]''. In this work, Bacon rejects the syllogistic method of Aristotle in favor of an alternative procedure "which by slow and faithful toil gathers information from things and brings it into understanding".<ref>Farrington, 1964, 89</ref> This method is known as [[inductive reasoning]], a method which starts from empirical observation and proceeds to lower axioms or propositions; from these lower axioms, more general ones can be induced. For example, in finding the cause of a ''phenomenal nature'' such as heat, three lists should be constructed:
* The presence list: a list of every situation where heat is found.
* The absence list: a list of every situation that is similar to at least one of those of the presence list, except for the lack of heat.
* The variability list: a list of every situation where heat can vary.
Then, the ''form nature'' (or cause) of heat may be defined as that which is common to every situation of the presence list, and which is lacking from every situation of the absence list, and which varies by degree in every situation of the variability list.

Other works in the textbook tradition include [[Isaac Watts]]'s ''Logick: Or, the Right Use of Reason'' (1725), [[Richard Whately]]'s ''Logic'' (1826), and [[John Stuart Mill]]'s ''A System of Logic'' (1843). Although the latter was one of the last great works in the tradition, Mill's view that the foundations of logic lie in introspection<ref>N. Abbagnano, "Psychologism" in P. Edwards (ed) ''The Encyclopaedia of Philosophy'', MacMillan, 1967</ref> influenced the view that logic is best understood as a branch of psychology, a view which dominated the next fifty years of its development, especially in Germany.<ref>Of the German literature in this period, Robert Adamson wrote "''Logics'' swarm as bees in springtime..."; Robert Adamson, ''A Short History of Logic'', Wm. Blackwood & Sons, 1911, page 242</ref>