After Introducing my new project which is a living handbook on historical literary concepts in Arabic and their translation (KALiMaT), I will interrogate the historical term adab in its foundational period to revisit our modern understanding of literature. I will begin this paper with some critical remarks on what I call a literary history of concepts. I suggest that literary history should focus on the dynamic modes of interpretation within and between works and texts, taking into account the material, social, and discursive boundaries of textual production. Secondly, a literary conceptual history does not examine literature as a predefined concept but takes the concept of literature itself as the main object of examination. The central Arabic term that inevitably emerges in this regard is adab with its inexhaustible richness of facets and historical variability, as several recent publications have shown. I will discuss some of these recent contributions and translations of adab and then explain my argument that, despite the obvious diachronic polysemy, adab was a very clear-cut matter for authors of the 2nd and 3rd centuries AH, which is usually considered the founding period of Arabic literature. Just ‘like death, adab is indispensable,’ writes Ibn al-Muqaffaʿ in his famous preface to Kalīla and Dimna. And Ibn Qutayba, in his ʿUyūn al-akhbār (The Essential Accounts), considers the ‘acquisition of adab’ (taʾaddub) the essential asset for his fellow scribes and administrators. Both authors emphasize the necessity to combine adab with reason (ʿaql) in several of their writings, pointing to a particular kind of relationship between theory and practice. In these writings, as I will finally argue, adab is a core ethical concept, a kind of meta-knowledge, that offers the possibility to ascribe transformative, existential, and transcendental dimensions to literature.