This study offers a new interpretation of Avicenna's philosophy and its problematic nexus with mysticism. In two of his philosophical summae, Avicenna develops some problems concerning the verifiability of empirical statements and the knowledge of the First Principle, i.e., the Necessary Existent. Considering the limits of speculative knowledge regarding both the empirical and the metaphysical domains, Avicenna ponders different practical ways of relating to the First Principle: prophethood or lawmaking (nubuwa), the religious observance of law (ibada), ascetism (riyada), and philosophy. We will see that a higher philosophical practice (distinctive of the arifun, knowers or gnostics, and characterized for the detachment of the physical world) strongly diverges from the rest of those traditional ways of practical and political life.