Faced by the ambiguity of the Greek term δύναμις in the first five chapters of Plotinus, Enneads IV.4 (28), the Arabic Adaptor responsible for the pseudonymous Theology of Aristotle develops a highly original doctrine of the reversal of roles between power or potency (Greek δύναμις /Arabic al-quwwa) and act, action or actuality (Greek ἐνέργεια/Arabic al-fiʿl) in the intelligible and the sensible world respectively. Whereas act is dominant in the sensible world, says the Adaptor, where power/potency must be led or bought to act, it is power perfect and complete (tāmmatun kāmilatun) that reigns in the intelligible world. This is explaine by the doctrine of the barks or shells (al-qušūr) which veil both the soul and the objects of its cognition in the sensible world, a doctrine which may have been present in Porphyry. Another result of the Adaptor’s careful, insightful confrontation with Plotinus’s text is that of a separate faculty able to perceive the intelligibles even during life on earth, the possession of which is exclusively reserved for a spiritual élite described as the “people of happiness” (ahl al-saʿāda). The text of the ThA thus preserves a key episode in the history of the interpretation of the notions of potentiality and act.