"The fullest meaning of the intellect and its universal function is to be found in the ma‘rifah or gnosis, which lies at the heart of the Islamic revelation and which is crystallized in the esoteric dimension of Islam identified for the most part with Sufism. There are verses of the Quran and hadiths of the Prophet that allude to the heart as the seat of intelligence and knowledge. The heart is the instrument of true knowledge, as its affliction is the cause of ignorance and forgetfulness. That is why the message of the revelation addresses the heart more than the mind as the following verses of the Quran reveal: O men, now there has come to you an admonition from your Lord and a healing for what is in the breasts (namely the heart) and a guidance, and a mercy to the believers. Surah (10:57) (Arberry translation)"