Francis Ellingwood Abbot (1836-1903), was a Unitarian minister and a radical religious philosopher. Abbot founded the Free Religious Association (1867), was editor of the weekly publication The Index (1870-1880), and organizer and President of the National Liberal League. He earned an A.B. at Harvard University in 1855 and a Ph.D and A.M. in 1881. Abbot taught philosophy briefly at Harvard University in 1887.