In this chapter, meanings of the divine name al-Ḥaqq are explored. Among Sufis, al-Ḥaqq became the most prevalent from among the divine names, substituting even the supreme name ‘Allāh’. Despite its complex meanings and ambiguous grammatical function, it came to imply, almost unanimously, ‘ultimate Truth’, ‘Reality’. But for al-Ḥakīm al-Tirmidhī, rather than a divine name, al-ḥaqq signifies a personified power, a hypostasis, a mediator between God and human beings in charge of law and order. Such personification, which al-Tirmidhī exhibits throughout his works, singles him out from his contemporaries. It is part of his cosmic view, according to which everything has a polar counterpart. Al-ḥaqq’s counterpart is raḥma (Mercy). Universal polarity prevails in all realms of existence: in the divine attributes of Majesty (jalāl) versus Beauty (jamāl), as well as in the polar mystical states of fear and hope, contraction and expansion, annihilation and permanence (baqāʾ) and more. On the Day of Judgement, the strict, uncompromising power of al-ḥaqq will be mitigated by al-raḥma, Mercy, in a triadic scene in which Allāh will preside over the two polar powers. This binary teaching bears strong echoes of pre-Islamic, late antique systems.