People
Read – let me charge you to read. Study books that treat of your profession, and of history.
— Admiral Collingwood

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The repeated instruction to read gives the passage an urgent, almost commanding tone. The speaker names professional study and history as the subjects to pursue. The wording treats reading as a serious responsibility, joining attention to one's occupation with attention to the past.
Context reviewed