I am firmly convinced that many of the shortcomings of current grammatical theory are due to the fact that grammar has been chiefly studied in connexion with ancient languages known only through the medium of writing, and that a correct apprehension of the essential nature of language can only be obtained when the study is based in the first place on direct observation of living speech and only secondarily on written and printed documents.
In more than one sense a modern grammarian should be
novarum rerum studiosus.- A very influential product in its day.
https://ulozto.net/file/dbP8SUf3fh5L/jespphilg-rar