Creator's Description: the article focuses on the Crystal Mirror of Tenet Systems by Thu'u bkwan Blo bzang chos kyi nyi ma (1737-1802). It traces the history of the text and its reception, analyzes its genre, and examines in some detail the question of Thu'u bkwan's oft-alleged impartiality toward the various Tibetan orders that he describes. The latter is explored through an analysis of the rhetoric he employs in discussing three traditions: the Jo nang, the Dge lugs, and the Rnying ma. While Thu'u bkwan clearly is more favorable to some traditions than others (and the Dge lugs above all), he also defends traditions like the Rnying ma against certain criticisms, some of which may come from Dge lugs quarters. And even the Jo nang, though disparaged, is not so unequivocally condemned that some virtues are not acknowledged. The conclusion is that although Thu'u bkwan may not approximate today's ideal of dispassionate scholarship, he does seem on balance to be reasonably fair within the context of premodern Tibetan intellectual discourse.