Robert Owen's Opening Speech, and His Reply to the Rev. Alex. Campbell, in the Recent Public Discussion in Cincinnati: To Prove that the Principles of All Religions are Erroneous, and that Their Practice is Injurious to the Human Race. Also, Mr. Owen's Memorial to the Republic of Mexico, and a Narrative of the Proceedings Thereon ... for the Purpose of Establishing a New Political and Moral System of Government, Founded on the Laws of Nature, as Explained in the Above Debate with Mr. Campbell