There can be nothing more utterly subversive of all that is really valuable than the suppression of honest thought. No man, worthy of the form he bears, will at the command of church or state solemnly repeat a creed his reason scorns.

Robert Green Ingersoll (1833-1899) American lawyer, freethinker, orator

Lecture (1873-12) “Individuality,” Chicago Free Religious Society
    (Source)

Full title "Arraignment of the Church and a Plea for Individuality." Collected in The Gods and Other Lectures (1876)