I don't think anyone used the term category theory (in the mathematical sense) before mathematical biologist Robert Rosen in 1958. That is the earliest reference known to Math Reviews. Not surprising, it was slow to spread from Rosen into the field. Saunders mentioned "the theory of categories" once in his 1963 book Homology (p. 34). In that book he writes repeatedly of set theory, group theory, homology theory, and many others, but not once "category theory". One other datum: Freyd's 1960 dissertation was titled "Functor theory," but "category theory" occurs in the introduction to the 1964 book version. Category theory was a very common term by the late 1960s. Good question about "category theorist." I have no idea but expect it came several years later. It is not used very formally, and searching it on Math Reviews gives only 15 hits in the entire database. Colin On 7/10/19 7:01 AM, David Roberts wrote:
Hi all,
the (idle) question is: when did the phrase 'category theory' catch on for the field? Clearly it didn't leap from either of the heads of Eilenberg or Mac Lane full-grown, since they used the phrase 'General theory of natural equivalences'. There are the old 'Reports of the Midwest Category Seminar' lecture notes (the first in 1967), which hints that 'category theory' wasn't quite the name in use.
Even more interesting: who was the first "category theorist", by that name?
Answers referring to verifiable sources would be best.
Thoughts?
David
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]