In the history of mathematics, Charles Lutwidge Dodgson (1832-1898), better known as Lewis Carroll, stands out as the rare mathematician who also was an exceptional literary figure. In The Pamphlets of Lewis Carroll, each volume of a projected six volumes deals with a particular aspect of his work. When the series is complete, it will include all of his works that were not originally issued in hard cover with the exception of his poetry and fiction. This fourth volume focuses on his writings on logic. It includes pamphlets and sheets privately printed by Dodgson, unpublished manuscript sheets, rare previously published documents, and early versions of published works. These are collected together for the first time, organized by subject, and presented with suitable commentary so that the reader can fully appreciate Dodgson's contributions to the logic of his time and of ours. The general introduction to the book describes the importance of logic in Dodgson's life and work and provides a historical perspective on the state of logic that existed during his lifetime. The sections of the book that follow contain introductory essays that provide analyses and context both for the general reader and for the specialist, followed by the items in transcription or facsimile.