Full Idea
A variable in a proposition of logic ....has the status of a mere auxiliary notion that is really inappropriate to the constant, 'eternal' essence of the propositions of logic.
Gist of Idea
Variables are auxiliary notions, and not part of the 'eternal' essence of logic
Source
Moses Schönfinkel (Building Blocks of Mathematical Logic [1924], §1)
Book Reference
'From Frege to Gödel 1879-1931', ed/tr. Heijenoort,Jean van [Harvard 1967], p.359
A Reaction
He presumably thinks that what the variables stand for (and he mentions 'argument places' and 'operators') will be included in the essence. My attention was caught by the thought that he takes logic to have an essence.
Related Idea
Idea 18895 Logic which maps ordinary reasoning must be transparent, and free of variables [Sommers]