 His other works mainly deal with philosophical theology, such as al-Hikma al-‘arshiyya (Wisdom of the throne) and al-Shawahid al-rububiyya (Divine witnesses). One work, al-Masha‘ir (Inspired recognitions) stands out as a dense epitome of his doctrine of being as expressed in the first part of the Four Journeys on the semantics of existence. As a religious thinker, Mulla Sadra was also keen to come to terms with his scriptural heritage, and he wrote three works on the hermeneutics of the Qur’an as a preparation for his own incomplete mystical and philosophical commentary on the text: Mafatih al-ghayb (Keys to the unseen), Asrar al-ayat (Secrets of the verses/signs), and Mutashabihat al-Qur’an (Allegories of the Qur’an). As a Shi‘i thinker, he also wrote an incomplete commentary on the main doctrinal collection of tradition, Usul al-kafi of Kulayni (d. 329 AH/941), as an attempt to grapple with the question of what it means to be an intuitive philosopher in the Shi‘i tradition. He also wrote a number of other treatises on particular issues, such as creatio ex nihilo (huduth al-‘alam), the resurrection, the nature of knowledge, logic, and the relationship between existence and essence. But the Four Journeys remains his most important work and the key to understanding his philosophy as he repeatedly cited it in his other works for a more extended discussion of an issue.