- Liberty in the Nineteenth Century
- Frederick Douglass: the Colored Orator
- Atheists and agnostics: a protest against their disabilities before the law : a lecture delivered in Investigator Hall, Boston, to the Ingersoll Secular Society on Sunday March 1, 1885.
- The Rise of Intellectual Liberty From Thales to Copernicus
- The Revolutions of 1688 and 1776