The best teacher is the one who suggests rather than dogmatizes, and inspires his listener with the wish to teach himself.

Edward George Bulwer-Lytton (1803-1873) English novelist and politician

Kenelm Chillingly: His Adventures and Opinions, Book 3, ch. 12 [Kenelm] (1873)
    (Source)

Sometimes given as “The best teacher is the one who suggests rather than dogmatizes and inspires rather than instructs.”