Columbia subject headings:
Harvard subject headings:
Hugo, Victor, 1802-1885--Knowledge--Literature.
Hugo, Victor, 1802-1885--Philosophy.
Influence (Literary, artistic, etc.)
Philosophy in literature.
Rousseau, Jean-Jacques, 1712-1778--Influence--Hugo.
Rousseau, Jean-Jacques, 1712-1778--Influence.
Voltaire, 1694-1778--Influence.
Princeton subject headings:
Hugo, Victor, 1802-1885--Political and social views.
Rousseau, Jean-Jacques, 1712-1778--Influence.
Voltaire, 1694-1778--Influence.