Scholars have shown that historicizing studies of sight can shed light on everything from art history to statecraft to scientific inquiry. But the disciplined eye of the scholar of language—the philological observer—has received little attention, an omission particularly worthy of notice given recent interest in how the history of humanities might be incorporated into the history of science more broadly. This article contributes to a treatment of philological observation in the nineteenth century. Focusing particularly on the career of the Munich Latinist Eduard Wölfflin (1831–1908), a founding father of the monumental Latin lexicon known as the Thesaurus linguae Latinae, it isolates three distinct modes of philological observation: the constitutive, the collative, and the estimative. In the process, it indicates parallels between the kinds of sight practiced by philologists and those of their contemporaries in other investigative arenas, showing how developments on a Latinist's desk can be tied into much larger networks of cultural and epistemic concerns