According to Turner 's prospectus for the Liber Studiorum, it was intended 'to attempt a classification of the various styles of landscape, viz., the historic, mountainous, pastoral, marine, and architectural' ( Rawlinson, Turner's Liber Studiorum, p. xviii). However, it has often been supposed that the work had some other unifying meaning beyond the mere classification of landscape. Turner himself insisted that the series was of no use except together (see Rawlinson, Turner's Liber Studiorum, p. li, and Works, 7.434). It has been suggested that the series 'was conceived from the first as a kind of visual treatise on landscape art, and is the central document of Turner the theorist of painting' ( Butlin, Gage, Joll, and Wilton, Turner 1775-1851, p. 61). More recently it has been suggested that Turner himself 'was unable to arrive at a definitive summary of what his own series was about', and that we might regard it in terms of an 'amalgam of different models' including the Liber Veritatis of Claude; the topographical part-work; a classification of landscape; a propaganda document intended to elevate the status of landscape art; and the concept of the drawing book (see Forrester, Turner's Drawing Book, pp. 27-37).
The importance of the Liber Studiorum for Ruskin was considerable: it was a major influence on his development as a critic, and as an artist.