 Muslims could not afford to overlook. As a mathematician he realized the importance of Aristotelian Logic, However, al-Kindi found Aristotelian metaphysics contradictory; that Aristotle did not offer valid logical support to the issue of the eternity of the world.
 Al-Kindi in his mathematical philosophy presented an argument that actual infinity is self-canceling. Also in his philosophy of nature he showed that matter, motion, and time as closely related concepts (this is an advanced worked comparing it with the knowledge of the middle ages.) Since matter cannot be eternal, and cannot generate its existence (c.f. essence and generation argument) then its motion and time are not eternal too. Al-Kindi was the first Muslim philosopher to note clearly that the metaphysics of the Greek philosophers is first self contradictory, and second it contradict the Islamic belief. He also gave a religious basis for studying these fields.
 Al-Kindi would prove to be the most difficult Islamic thinker to study which explains the dearth of works on him. This is due to a variety of reasons some of which is that he was a scientist, philosopher of science, a rigorous mathematician and a man of letters with a high command of Arabic. One who is not well versed in all of these topics in addition to a solid grasp of scientific Arabic would not be able to fully appreciate al-Kindi nor his contributions.
 Then it would be up to al-Farabi (870-950) [who served in the Hamdanid court in Aleppo, northern Syria.] that would formulate philosophy in a manner that would be palatable to Muslim tastes. His efforts would be aimed at expounding philosophy in Islamic terms. It is worthwhile to note that in his lifetime he was not a noted figure in field. Actually, Avicenna is the one that popularized his writings. He became known as the Second teacher (after Aristotle). He also laid an important groundwork in every major field of philosophy and most importantly political philosophy. He would be the credited with the popularizing neo-Platonism in the Muslim world.
 Important to Islamic philosophers is the concept of Prophethood, namely God selecting messengers and endowing them through prophecy (communication from God, either directly or through Angels) with enlightenment and truth. This was a concept that would have to be explained philosophically. It would be al-Farabi who would formulate such a concept in Hellenistic terms. To al-Farabi, he would equate two sources of knowledge namely revelation and philosophy as the two roads to enlightenment and truth.
 Al-Farabi had accomplished much in all the major fields of philosophy including metaphysics, logic, music theory, ethics and politics. Not only did he make a brave attempt to reconcile philosophy with Islamic doctrine, he also attempted to reconcile philosophy with it self, namely a work on the philosophy of Plato and Aristotle (available online c.f. al-Farabi). He was also an accomplished musician of great renown.
 Soon thereafter, a hodgepodge work called the epistles of the brethren of purity “Rasil Ikhwan al-Safa”. (ca. 946-1055) This work is a mix of philosophy (Pythagorean speculations), theology (Jewish, Christian, Persian, Hindu, and Islamic elements), mysticism, math, music theory, and astrology. Prof. Hitti, in his history of the Arabs says of the group “...they evidently aimed to overthrow [Abbasid rule] by undermining the popular intellectual system and religious beliefs.” p. 373. It is important to note they were aligned with the Fatimid rule.
 The third most important figure in philosophy is Ibn Sina (Avicenna) (980-1037) [He lived in Northern Iran/FSSR]. He wrote on a wide variety of sciences, medicine being his most valuable contribution. He also wrote on all branches of philosophy. He is also credited with popularizing philosophy for the elite. There are many legends that surround not only his life but there are many books that are attributed to him that he did not write according to scholarly accounts. Still he wrote extensively on philosophy ranging from short works to encyclopedic leng