Abul Abbas Fadl Ibn Muhammed Lawkari was a prominent literary man, mathematician, and philosopher of the 5th century (AH). Through one intermediary, he was a student of Ibn Sina and a student of Bahmanyar and, through three intermediaries; he was a master of Khwajah Nasir al-Din Tusi. Lawkari was a well-known literary man who wrote poems in both Persian and Arabic. He had a collection of poems (diwan) from which only a few couplets are left. In addition, he left a treatise in which he presented all the principles of all axiomatic sciences, that is, logic, physics, ethics, mathematics, and practical wisdom in verse in Persian and explained them in eloquent Persian prose. Lawkari was a prominent mathematician who was assigned to compile the history of Jalali Malekshahi with the cooperation of some other mathematicians and astronomers such as Khayam Nishaburi, Khazani, Asfazari, and Vaseti. In the month of Ramezan of 471 AH, they moved the beginning of the month of Farvardin to the first of “haml” (Aries).He was one of the great philosophers of the 5th century who enjoyed complete mastery over the Peripatetic philosophy and spread philosophy in Khorasan. He trained some distinguished and famous students such as Qutb al-Zaman Tabasi Marwazi, ‘Abdulrazzaq Turki, and Sharaf al-Zaman Ilaqi. He also wrote a book called Bayan al-haq biziman al-sidq, which was a complete collection on all the axiomatic sciences of Peripatetic philosophy, intended to be used as a textbook. This work includes a summary of all the main problems of Peripatetic philosophy from the time of Aristotle until Bahmanyar. Of course, in spite of its brevity, it makes students of philosophy needless of all books on Peripatetic philosophers.Lawkari lived during the reign of Ghaznavid and Saljuk dynasties, i.e. during the period of the decline of rational sciences. Finally, with the rise of Abu Hamed Muhammed Ghazzali, the sworn enemy of philosophy, the chain of Peripatetic philosophers came to an end with Lawkari, and he was in fact the last Peripatetic philosopher in its particular sense. However, it must be added that, although rational sciences were greatly damaged by his demise, later they came back to the field of knowledge even stronger than before.