Unjust laws exist: shall we be content to obey them, or shall we endeavor to amend them, and obey them until we have succeeded, or shall we transgress them at once?

Henry David Thoreau (1817-1862) American philosopher and writer

Essay (1849-05), “Resistance to Civil Government [On the Duty of Civil Disobedience],” Æsthetic Papers, No. 1, Article 10
    (Source)

Based on an 1848 lecture at the Concord Lyceum.