en.wikipedia.org/wiki/Modal_logic
1 correction found
the first modal axiomatic systems were developed by C. I. Lewis in 1912.
Lewis's modal work began in 1912, but standard histories place the first modal systems in 1918, not 1912.
Full reasoning
This gets the timeline wrong by conflating the start of Lewis's work with the date of the first systems.
The Stanford Encyclopedia of Philosophy's history article on modal logic states that the historical development runs "from C.I. Lewis's pioneering work starting in 1912, with the first systems devised in 1918." So 1912 marks the beginning of Lewis's pioneering work, but not the date when the first modal axiomatic systems were developed.
In other words, the article should distinguish between:
- 1912: Lewis begins the line of work.
- 1918: the first systems are devised.
As written, the sentence attributes the first modal axiomatic systems to the wrong year.
1 source
- Modern Origins of Modal Logic (Stanford Encyclopedia of Philosophy)
the historical development of systems of modal logic... from C.I. Lewis's pioneering work starting in 1912, with the first systems devised in 1918, to S. Kripke's work in the early 1960s.