In several passages of the Arabic commentaries on Aristotle’s Rhetoric , the Greek term hexis (gr. ἕξις , stable disposition to produce certain acts) is rendered by himma (aspiration), whose definition is taken in a politico-psychological sense. Other passages of these commentaries and other works of philosophy written in Arabic attest for the presence of himma with the same meaning, and with significant frequency and in crucial passages – despite the term’s absence from the indexes of modern editions of these texts. The present article proposes an exhaustive study of the definitions of himma employed in its politico-psychological sense and of its characteristics outside the definitions before comparing it, on the one hand, with other acceptions of himma – ṣiġar al-himma (pusillanimity), kibar al-himma (magnanimity), the himmas as different energies of the soul, the himma according to the sūfīs , the himma at the source of the himmas – and, on the other hand, with the Aristotelian hexis , with malaka , and with the Stoic hexis . Finally, we attempt to identify the origines of the concept of himma in its politico-psychological sense.