Lawson had the pedagogic instinct; whenever he found anything out he was eager to impart it; and because he taught with delight he talked with profit. Philip, without thinking anything about it, had got into the habit of sitting by his side.
Of Human Bondage by W. Somerset Maugham
Does the 'profit' here mean 'advantage'? If so, whose advantage does this sentence mean? talker or listener?
Maugham is echoing a very famous line from the Art of Poetry by the Roman poet Horace, which every educated reader of Maugham's generation would recognize. Here's Ben Jonson's translation (1640):
Poets would either profit or delight,
Or mixing sweet and fit, teach life the right.
In applying the tag to a teacher, Maugham cleverly twists its sense: because Larson delights in teaching, his teaching is profitable to those whom he teaches.
