Insān Kāmil is the Perfect Man, the central figure of the later, philosophical Sufism associated with Ibn al-ʿArabī and developed most systematically by ʿAbd al-Karīm al-Jīlī. On this site the doctrine appears in Nicholson’s second chapter of Studies in Islamic Mysticism, which is an exposition of al-Jīlī. It differs in tone from the practical manuals (the Kashf, the Awārif) because it asks a metaphysical question: what is the human being for?
Nicholson’s summary of the idea comes in two sentences:
While every appearance shows some attribute of reality, Man is the microcosm in which all attributes are united, and in him alone does the Absolute become conscious of itself in all its diverse aspects.
And the corollary:
God and man become one in the Perfect Man—the enraptured prophet or saint—whose religious function as a mediator between man and God corresponds with his metaphysical function as the unifying principle by means of which the opposed terms of reality and appearance are harmonised.
Nicholson adds the statement that makes the idea a matter of practical hope as well as theory: “Now, all men are perfect potentially, but few are actually so. These few are the prophets and saints.”
The Perfect Man is also given a cosmic office. “Jílí,” writes Nicholson, “calls the Perfect Man the preserver of the universe, the Quṭb or Pole on which all the spheres of existence revolve.” And his place in creation is explained in terms of purpose:
He is the final cause of creation, i.e., the means by which God sees Himself, for the Divine names and attributes cannot be seen, as a whole, except in the Perfect Man.
In the first phase of the process Nicholson outlines, “called the Illumination of the Names,” the Perfect Man “receives the mystery that is conveyed by each of the names of God, and he becomes one with the name in such sort that he answers the prayer of any person who invokes God by the name in question.” The Quṭb here is the same office that al-Hujwīrī places at the head of the hidden hierarchy of saints (Walī and Awliyāʾ); Nicholson notes that the popular belief in saintly mediators is the everyday counterpart of the metaphysical doctrine. In his own words, “The Perfect Man ... unites the One and the Many, so that the universe depends on him for its continued existence.”
Al-Jīlī does not leave the figure abstract. Nicholson reports that “Jílí remains a Moslem in spite of his philosophy, and for him this absolutely Perfect Man is the Prophet Mohammed.” Nicholson’s stance as a scholar is worth noting. He quotes verses in which al-Jīlī describes the Perfect Man’s threefold nature, and calls them verses “which no one can read without wondering how a Moslem could have written them.”
One way to relate the doctrine to the practical texts is to read it as the far end of the same path. The seeker who completes the work of passing away and subsistence is, in this vocabulary, one who has realised what the Perfect Man is potentially. See also Tawḥīd, ʿIlm and Maʿrifat, and the teacher who guides toward it.
The passages above are quoted from complete public-domain translations, all of which are free to read here in full.
Read Studies in Islamic Mysticism