y. 
Ibn Khaldun acknowledges that there are turning points in history. He wrote that in his time, he believed the Black Death and Mongol invasions were turning points, as was the development of Europe.
Ibn Khaldun's observations and research focused on the etiology of civilizational decline, “the symptoms and the nature of the ills from which civilizations die.” 
Ibn Khaldun's thesis, that the conquered race will always emulate the conqueror in every way,  and his theory about asbyiah (group feeling / party spirit) and the role it plays in Bedouin societies is insightful. The genius of this work is his study of the science of human culture, the rise and fall of empires, Ibn Khaldun termed this the science of umran (civilization), and it contains many pearls of wisdom. His “Introduction” is his greatest legacy, left for all of humanity and generations to come.
L. E. Goodman prepared a comparative study of Thucydides, who is considered the ‘father of history’, and the Muqaddimah. Goodman reveals the similarities in methods, assumptions, and conclusions, and notes that
Both men are naturalists, both empiricists, both exponents of a critical approach to historiography. Yet neither is a reductionist. Both seek a lesson in history, and both believe that the message of history is to be discovered in the careful study of historical laws revealed in the play of forces which are the expression of man's political and social nature. But beyond similarities of approach, there is a deep congruity of thought between the two authors, for both believe themselves to have glimpsed the pattern, learned the lesson of history. Both Ibn Khaldun and Thucydides have been led by their study of history to a cyclical, rather than linear view of historical process; both have been led, in developing their concepts of human and political reality, to a qualified relativism, which affords them … a cautious but by no means pessimistic historical theodicy. 
Although Goodman finds similarities between some of the historical theories of the two historians, there is little proof that the ideas of Thucydides ever appeared in Arabic. Further, as is the case with Ibn Khaldun, not many of their ideas have borne fruit, except perhaps in the modern period. Ibn Khaldun remains a highly vibrant and original thinker not only in the field of history but in sociology as well.
Ibn Khaldun’s view on science followed the traditional division of sciences, which involves a division into religious sciences and non-religious sciences. The non-religious sciences are further divided into useful and non-useful sciences (mainly the occult sciences such as magic, alchemy and astrology). In the Muqaddimah, Ibn Khaldun reports on all the sciences up to his time, with examples and quotations. He makes it a point to refute magic, alchemy, astrology, and philosophy in his book. His work became a record of the development of sciences in his day.
IBN KHALDUN'S VIEW ON PHILOSOPHY
Ibn Khaldun's view on philosophy is similar to that of al-Ghazali, in the sense that he attempted to reconcile mysticism and theology. In fact, Ibn Khaldun, according to Issawi,
…goes further than the latter [al-Ghazali] in bringing mysticism completely within the purview of the jurisprudent (faqih) and in developing a model of the Sufi shaykh, or master, as rather similar to the theologian. Philosophy was regarded as going beyond its appropriate level of discourse, in that 'the intellect should not be used to weigh such matters as the oneness of God, the other world, the truth of prophecy, the real character of the divine attributes, or anything else that lies beyond the level of the intellect' (Muqaddima 3, 38).
1. Mohammad A. Enan, Ibn Khaldun: His life and Work (New Delhi: Kitab Bhavan, 1979), 3-5. The author questions Ibn Khaldun’s Arab origin, although he does admit that he came from an influential family, which was politically active in Andalusian affairs. He also admits that the Arabs held the authoritative positions while the Berbers bore the brunt of the battles, thus indirectly admitting that Ibn Khald