The church has ever opposed the progress of woman on the ground that her freedom would lead to immorality. We ask the church to have more confidence in women. We ask the opponents of this movement to reverse the methods of the church, which aims to keep women moral by keeping them in fear and in ignorance, and to inculcate into them a higher and truer morality based upon knowledge. And ours is the morality of knowledge. If we cannot trust woman with the knowledge of her own body, then I claim that two thousand years of Christian teaching has proved to be a failure.

The Morality of Birth Control, 18 November 1921, Park Theatre, NY

American Rhetoric: Margaret Sanger -- The Morality of Birth Control[americanrhetoric.com]