Christian Science is a 1907 book by the American writer Mark Twain (1835–1910). The book is a collection of essays Twain wrote about Christian Science, beginning with an article that was published in Cosmopolitan in 1899. Although Twain was interested in mental healing and the ideas behind Christian Science, he was hostile towards its founder, Mary Baker Eddy (1821–1910).

Book I of this volume occupies a quarter or a third of the volume, and consists of matter written about four years ago, but not hitherto published in book form. It contained errors of judgment and of fact. I have now corrected these to the best of my ability and later knowledge.

Book II was written at the beginning of 1903, and has not until now appeared in any form. In it my purpose has been to present a character- portrait of Mrs. Eddy, drawn from her own acts and words solely, not from hearsay and rumor; and to explain the nature and scope of her Monarchy, as revealed in the Laws by which she governs it, and which she wrote herself.

Book I of this volume occupies a quarter or a third of the volume, and consists of matter written about four years ago, but not hitherto published in book form. It contained errors of judgment and of fact. I have now corrected these to the best of my ability and later knowledge.

Book II was written at the beginning of 1903, and has not until now appeared in any form. In it my purpose has been to present a character- portrait of Mrs. Eddy, drawn from her own acts and words solely, not from hearsay and rumor; and to explain the nature and scope of her Monarchy, as revealed in the Laws by which she governs it, and which she wrote herself.