On page 443, section 1.1 Expanding to Contradiction, in José Ferreirós' A Road To Modern Logic - An Interpretation, the following is written:
Philosophical conceptions of logic have been complex and varied; here we are only interested in the tradition of ‘formal logic’, and formal logic meant the theory of the syllogisms—above all the Aristotelian syllogisms but also the so-called hypothetical and disjunctive syllogisms.
Prior to reading the above quote, and this Wikipedia article linking to it, I had only read formal logic as referring to the larger, formalized study of logic (see this Britannica article for an example). This leads me to think there has been a shift in the use of the term, its use originating as a name for all syllogisitic logics, before being appropriated as a the name for the discipline of studying, creating and using formalized logics.
So, my two questions are mostly about etymology and usage, which does place this question scarily close to belonging in EL&U; however, I deem this question a bit too technical to be a good fit for that site, in that it requires an educated parsing of the logics discussed in relevant texts in order to know how and why the categorizes were composed. That's the etymology part, which is history (linguistic history, but history nonetheless). The usage part is less justifiable, but I am asking about a not so extensive account of the current usage from a historical perspective; as in, how is it different from the past and why.
So, to be completely clear, here are my questions:
- What did formal logic mean before?
- What does it mean now, and why has this changed?