One characteristic of professionals is that they reflect on the nature of their discipline; attention to the history of one's discipline is an important way of doing this. Efforts to trace the historical roots of vocational theory have been successful only as far back as late Renaissance Spain and southern Europe, notably in Chabassus and Zytowski's (1987) discussion of Sanchez de Arevalo's (1468) Speculum Vitae Humanae (Mirror of Human Life). We locate some recognizably modern concepts in a 10th-century Iraqi text, the Rasa'il Ikhwàn al-Safá wa-Khillan al-Wafa, or Treatises of the Brothers of Purity (Ikhwàn al-Safá, 955/1928).