It is a great misfortune to be alone, my friends; and it must be believed that solitude can quickly destroy reason.

[Malheur à qui est seul, mes amis, et il faut croire que l’isolement a vite fait de détruire la raison.]

Verne - misfortune to be alone - wist_info quote

Jules Verne (1828-1905) French novelist, poet, playwright
The Mysterious Island, Part 2, ch. 15 (1874) [tr. White (1876)]
    (Source)