Full Idea
Gentzen argued that the inferential role of a logical constant constitutes its meaning.
Gist of Idea
The inferential role of a logical constant constitutes its meaning
Source
report of Gerhard Gentzen (works [1938]) by Robert Hanna - Rationality and Logic 5.3
Book Reference
Hanna,Robert: 'Rationality and Logic' [MIT 2006], p.63
A Reaction
Possibly inspired by Wittgenstein's theory of meaning as use? This idea was the target of Prior's famous connective 'tonk', which has the role of implying anything you like, proving sentences which are not logical consequences.