The first major works of Sufism each systematically define the terms for drunkenness (sukr) and sobriety (sahw). This article attempts to trace the changes in the definitions of these terms in the tenth- and eleventh-century Sufi manuals, from the oldest example, Abū Nasr al-Sarrāj's (d. 378/988) Kitāb al-Luma‘ to ‘Alī Hujwīrī's (d. c. 467/1074) Kashf al-mahjūb, and to consider their implications. Hujwīrī provides an extensive debate about the relative value of the two experiences to which the terms refer, and associates arguments on either side with Abū Yazīd al-Bastāmī (d. 261/874–5?) and Abū l-Qāsim al-Junayd (d. 297/910), respectively. While the latter association stands out as innovative because previous commentators had not mentioned these individuals as exemplars of drunkenness and sobriety, it is argued here that Hujwīrī's choice was not entirely arbitrary, but a consequence of the dynamic nature of both biography and the definition of technical terminology.