In 570, Mohammed was born into a poor family among the nomadic tribes in the Arab Peninsula. Will Durant notes the significance of that birth:
No one in those years would have dreamed that within a century these nomads would conquer half of Byzantine Asia, all Persia and Egypt, most of North Africa, and be on their way to Spain. The explosion of the Arabian Peninsula into the conquest and conversion of half the Mediterranean world is the most extraordinary phenomenon in medieval history.
Mohammed established the third of the Abrahamic religions, Islam. Some of his ideas are of Jewish origin, and some of Christian origin. He generally accepted both Jewish and Christian scriptures as given by God to humankind, to which he added the Koran. That he wrote, was dictated to him by Gabriel during his visions. Islam shares some basic theological notions with Judaism and Christianity: one God, faith, repentance, the Last Judgment, prophecy, notions of heaven and hell, and notions of reward in an afterlife for faithful living.
During his lifetime, Mohammed sought to put an end to intertribal fighting among the Arabic tribes. However, he made no provision for his successor upon his death. Therefore, at his death, the intertribal conflict which he had managed during his life, erupted again, with increasing fervor, inflamed by Islamic ardor.
In his Story of Civilization, Volume IV, “the Age of Faith,” 11, at page 206, Will Durant observes this Islamic flowering:
Civilization is a union of soil and soul – the resources of the earth transformed by the desire and discipline of man. Behind the façade and under the burden, ports and palaces, temples and schools, letters and luxuries and arts, stands the basic man … All these were busy in Islam.
Islamic civilization arose in spectacularly short time during Europe’s Dark Ages. Then, as Europe emerged from the Middle Ages into the Renaissance, that civilization disintegrated about as fast as it arose.
At the end of the Middle Ages, as Christianity embarked upon its many Crusades, in the dealings between Christian and Muslim leaders, Muslims proved to be more honest and reliable than the various Christian groups embarking upon them.
Islamic civilization reached its zenith between 632 and 1058. Mohammed admired and encouraged the pursuit of knowledge. In its conquest of the Mediterranean, Islam came in contact with Greek culture, which inspired the Muslims to art and science. Education became an important role of the state. Arabic numbers were developed, and with them, logic, astronomy, and mathematics. As the Muslims expanded their territory, they learn from those that they conquered. As with the Christian monasteries, most mosques had libraries of that time.
Will Durant notes at page 237,
Nowhere else in those eighth, nineth, tenth, and eleventh centuries of our era was there so great a passion for books, unless it was in the China of Ming Huang. Islam reached then the summit of its cultural life. . . . The old cultures of the conquered were eagerly absorbed by the quick-witted Arabs; and the conquerors showed such tolerance that of the poets, scientists, and philosophers who now made Arabic the most learned and literary tongue in the world only a small minority were of Arab blood.
In 830, Islam established in Baghdad a “House of Wisdom” for scientific inquiry, an observatory, and a library. By the mid-ninth century, the Muslims had translated most of the classic Greek scientific texts and the works of Plato and Aristotle. During that time Muslim scholars attempted to reconcile the Koran to Greek philosophy. Algebra, quadratic equations, their analysis and solutions, geometry and trigonometry were developed during this period; astronomical tables were compiled; astronomical … calculations were determined with remarkable accuracy, and for the benefit of trade, maps of the lands within the scope of that civilization were developed. Muslims developed, long before Galileo, the notion that all things are attracted towards the center of the earth, that astronomical phenomena could be explained, as could the basics of genetics. Although Muslim religion prohibits the dissection of the human body, pharmaceuticals and therapy prospered. Arabic drugs were an important commodity in trade with Italy. They achieved an effective treatment of smallpox and measles, and some drugs were effective as an anesthetic inhalant. Many hospitals were established, medical care was provided for prisoners, and the insane were treated humanely. Their science explored the various models for the creation of mountains: either they resulted from the upheaval of the Earth’s crust or the eroding action of water. The scientist, Saracens, kept careful records of his observations of chemical experiments, establishing the roots of metallurgy and chemistry. Botanists develop skills of grafting, and in the ninth century Othman Amr-al-Jahiz developed a theory of evolution that began with basic matter, developed into the forms of plant life, through animal life, culminating in mankind.
One aspect of Islamic religion which was shared with both Judaism and Christianity was the age of the mystics. Will Durant notes that Islam was introduced to philosophy through its school of Muʿtazilah, meaning “seceders”. They denied the eternity of the Koran, but asserted that it arose through the dictation to Mohammed in time. They attempted to accord the Koran and the Hadith with the principles of logic and reason as the inherited them from the Greeks. They held that when the Hadith or Koran contradicted the teachings of reason, such passages must be interpreted allegorically.
Anticipating Maimonides, they held that mortal man cannot know the nature and extent of God; it could only recognize the spiritual power identified with God, as revealed in the world. That movement produced Al-Kindi, the first philosopher of conquest in Islam. He was a student of Neoplatonism and was a prolific writer on a great variety of mathematical, scientific and philosophical matters in Islam.
Will Durant, at page 251, notes the conflict that such philosophy created between the social and religious order and such logical demands:
In a society where government, law, and morality are bound up with a religious creed, any attack upon that creed is viewed as menacing the foundations of social order itself. . . . In this crisis three factors made orthodoxy victorious: a conservative caliph, the rise of the Turkish guard, and the natural loyalty of the people to their inherited beliefs.
The Shia sect of Islam was associated with Muʿtazilah and this new Islamic mysticism. With the Orthodox Islamic reaction, the Shia sect was marginalized, and their shrine was destroyed. They were to have great influence, however, upon Jewish and later Christian mysticism.