Question: English & Literature

What does the quote "thought out so many years ago, luminous with another than a professional light" mean from the book Heart of Darkness by Joseph Conrad?
In English & Literature | Asked by bookragstutor
Asked from the Heart of Darkness study pack

He's found an old book in the middle of the jungle and what it represents to him, apart from its literal information, is that in the middle of the jungle, civilization can still exist; a civil way of living can still exist; that the 'beast' in mankind need not come out to play once removed from society. 

MHood2 | 1483 days ago