In contrast to the Enlightenment, many historians of the early nineteenth century rehabilitated large areas of Scottish history as suitable for serious study. Lawyer and antiquarian Cosmo Innes, who produced works on "Scotland in the Middle Ages" (1860), and "Sketches of Early Scottish History" (1861), has been likened to the pioneering history of Georg Heinrich Pertz, one of the first writers to collate the major historical accounts of German history. Patrick Fraser Tytler's nine-volume history of Scotland (1828–43), particularity his sympathetic view of Mary, Queen of Scots, have led to comparisons with Leopold von Ranke, considered the father of modern scientific historical writing. Tytler was co-founder with Scott of the Bannatyne Society in 1823, which helped further the course of historical research in Scotland. Thomas M'Crie's (1797–1875) biographies of John Knox and Andrew Melville, figures generally savaged in the Enlightenment, helped rehabilitate their reputations. W. F. Skene's (1809–92) three part study of "Celtic Scotland" (1886–91) was the first serious investigation of the region and helped spawn the Scottish Celtic Revival. Issues of race became important, with Pinkerton, James Sibbald (1745–1803) and John Jamieson (1758–1839) subscribing to a theory of Picto-Gothicism, which postulated a Germanic origin for the Picts and the Scots language.