The concrete content – and thus the origin – of Islamic spirituality is the spiritual Substance of the Prophet, the Substance whose modalities Qushayri, Ibn al-‘Arif and others have tried to catalog by means of the notion of “stations” (maqamat). Sufism is the realization of Union, not only by starting from the idea of Unity that is both transcendent and immanent, but also, and correlatively, by being reintegrated into the hidden and yet ever-present Muhammadan Substance, directly or indirectly or in both ways at once: thus the mystical “traveller” (salik) may “follow the example of the Prophet” in a way that is either formal or formless, hence indirect or direct; for the Sunna is not just the multitude of precepts, it is also the “Muhammadan Substance”* of which these precepts are the reflections at various levels, and which coincides with the mystery of the “immanent Prophet.” In principle or in themselves the intrinsic qualities are independent of outward comportment, whereas the latter’s entire reason for being lies in the former; rather as, according to the Shaykh al-‘Alawi, the sufficient reason of the rites is the remembrance of God, which contains all rites in an undifferentiated synthesis. (* “And verily thou art of a supereminent nature” (la ‘ala khuluqin ‘azim): that is, of a most lofty character (Sura “The Pen,” 4).) (GTUFS: FaceA, The Mystery of the Prophetic Substance)
In fact, the term “Sufism” includes the most shallow fanaticism as well as the most profound speculation; now neither one nor the other constitutes total Tasawwuf, which goes without saying in the case of the first attitude, whereas the second is integral esoterism only on condition that it be accompanied by an appropriate method and not merely by pious observances, whose emotional accentuation moreover is scarcely compatible with the perspective of gnosis. Authentic esoterism – let us say it again – is the way it is founded on total or essential truth, and not merely on partial or formal truth, and which makes an operative use of the intelligence, and not only of the will and the feelings. The totality of truth demands the totality of man. (GTUFS: SufismVQ, Human Premises of a Religious Dilemma)
Sufism is “sincerity of faith” and this sincerity – which has absolutely nothing in common with the modern cult of sincerity – is, on the level of doctrine, nothing other than an intellectual vision that does not halt halfway but on the contrary draws from the idea of Unity its most rigorous consequences. The final term of this is not only the idea of the nothingness of the world but also that of the Supreme Identity and the corresponding realization: “the unity of Reality” (wahdat al-Wujud). (GTUFS: UIslam, The Path)
In defining Sufism as an ascesis, it is implicitly defined as a succession of realizatory and liberating Stations; and this corresponds perfectly to the specific nature of esoterism, which “transforms” man instead of simply saving him; or rather, which saves him in transforming him, and transforms him in saving him. (GTUFS: SurveyME, Enigma and Message of Islamic Esoterism)