The Quadripartite Division of the Intellect in Medieval Jewish Thought

Both al-Kindī and al-Fārābī divided the intellect into four stages. According to their division, the eternal intellect (Universal Intellect or Active Intellect) is counterpoised to the three stages of human intellect. Al-Fārābī replaced the al-Kindīan "Second Intellect" (al-ʿaql al-thānī) with his "Acquired Intellect" (ʿaql mustafād). Until the fourteenth century, these two quadripartite divisions of the intellect are found in Jewish philosophy without any essential change. In the fourteenth century the two divisions seem to have been joined together into one unit. Thus, the al-Kindīan "Second Intellect" became a separate intellect which emanated from the Active Intellect. The other three stages remained as they originally appeared in al-Fārābī's division. This scheme was developed by Ḥayyim Israeli and Shem Ṭov ibn Mayor in their commentaries on Abraham ibn Ezra's commentary to Gen 3:24.