Al-Ghazali in the context of "Qiyamah"

Ibn Rushd (14 April 1126 – 11 December 1198), Latinized as Averroes, was an Andalusian polymath and jurist who was proficient in a variety of intellectual fields, including philosophy, theology, medicine, astronomy, physics, psychology, mathematics, neurology, Islamic jurisprudence and law, and linguistics. The author of more than 100 books and treatises, his philosophical works include numerous commentaries on Aristotle, for which he was known in the Western world as "The Commentator" and "Father of Rationalism".

Averroes was a strong proponent of Aristotelianism; he attempted to restore what he considered the original teachings of Aristotle and opposed the Neoplatonist tendencies of earlier Muslim thinkers, such as al-Farabi and Avicenna. He also defended the pursuit of philosophy against criticism by Ash'ari theologians such as Al-Ghazali. Averroes argued that philosophy was permissible in Islam and even compulsory among certain elites. He also argued scriptural text should be interpreted allegorically if it appeared to contradict conclusions reached by reason and philosophy. In Islamic jurisprudence, he wrote the Bidāyat al-Mujtahid on the differences between Islamic schools of law and the principles that caused their differences. In medicine, he proposed a new theory of stroke, described the signs and symptoms of Parkinson's disease for the first time, and might have been the first to identify the retina as the part of the eye responsible for sensing light. His medical book Al-Kulliyat fi al-Tibb, translated into Latin and known as the Colliget, became a textbook in Europe for centuries.

Istislah (Arabic: استصلاح, lit. 'to deem proper') is a method employed by Islamic jurists to solve problems that find no clear answer in sacred religious texts. It is related to the term مصلحة Maslaha, or "public interest" (both words being derived from the same triconsonantal root, "ṣ-l-ḥ"). Extratextual pragmatic considerations are commonly accepted in Islamic jurisprudence concerning areas where the Qur'an and the practices of the earliest Muslim generations (Salaf) provide no specific guidance.

Istislah bears some similarities to the natural law tradition in the West, as exemplified by Thomas Aquinas. However, whereas natural law deems good that which is known self-evidently to be good, according as it tends towards the fulfilment of the person, istislah calls good whatever is connected to one of five "basic goods". Al-Ghazali abstracted these "basic goods" from the five legal precepts in the Qur'an and Sunnah—religion, life, reason, lineage (or offspring), and property. In this classical formulation, istislah differs from utilitarianism—"the greatest happiness for the greatest number of people"—because something that results in "the greatest happiness" may infringe any one of the five basic values. Rather than utilitarianism, Istislah bears closer resemblance to deontologicalism.

In Islam, "the promise and threat" (waʿd wa-waʿīd) of Judgement Day (Arabic: یوم القيامة, romanized: Yawm al-qiyāmah, lit. 'Day of Resurrection' or Arabic: یوم الدین, romanized: Yawm ad-din, lit. 'Day of Judgement'), is when "all bodies will be resurrected" from the dead, and "all people" are "called to account" for their deeds and their faith during their life on Earth. It has been called "the dominant message" of the holy book of Islam, the Quran, and resurrection and judgement the two themes "central to the understanding of Islamic eschatology."Judgement Day is considered a fundamental tenet of faith by all Muslims, and one of the six articles of Islamic faith.

The trials, tribulations, and details associated with it are detailed in the Quran and the Hadith (sayings of Muhammad); these have been elaborated on in creeds, Quranic commentaries (tafsịrs), theological writing, eschatological manuals to provide more details and a sequence of events on the Day. Islamic expositors and scholarly authorities who have explained the subject in detail include al-Ghazali, Ibn Kathir, Ibn Majah, Muhammad al-Bukhari, and Ibn Khuzaymah.

The existence of God is a subject of debate in the philosophy of religion and theology. A wide variety of arguments for and against the existence of God (with the same or similar arguments also generally being used when talking about the existence of multiple deities) can be categorized as logical, empirical, metaphysical, subjective, or scientific. In philosophical terms, the question of the existence of God involves the disciplines of epistemology (the nature and scope of knowledge) and ontology (study of the nature of being or existence) and the theory of value (since some definitions of God include perfection).

The Western tradition of philosophical discussion of the existence of God began with Plato and Aristotle, who made arguments for the existence of a being responsible for fashioning the universe, referred to as the demiurge or the unmoved mover, that today would be categorized as cosmological arguments. Other arguments for the existence of God have been proposed by St. Anselm, who formulated the first ontological argument; Thomas Aquinas, who presented his own version of the cosmological argument (the first way); René Descartes, who said that the existence of a benevolent God is logically necessary for the evidence of the senses to be meaningful. John Calvin argued for a sensus divinitatis, which gives each human a knowledge of God's existence. Islamic philosophers who developed arguments for the existence of God comprise Averroes, who made arguments influenced by Aristotle's concept of the unmoved mover; Al-Ghazali and Al-Kindi, who presented the Kalam cosmological argument; Avicenna, who presented the Proof of the Truthful; and Al-Farabi, who made Neoplatonic arguments.

Buridan's ass is an illustration of a paradox in philosophy in the conception of free will. It refers to a hypothetical situation wherein an ass (or donkey) that is equally hungry and thirsty is placed precisely midway between a stack of hay and a pail of water. Since the paradox assumes the ass will always go to whichever is closer, it dies of both hunger and thirst since it cannot make any rational decision between the hay and water. A common variant of the paradox substitutes the hay and water for two identical piles of hay; the ass, unable to choose between the two, dies of hunger.

The paradox is named after the 14th-century French philosopher Jean Buridan, whose philosophy of moral determinism it satirizes. Although the illustration is named after Buridan, philosophers have discussed the concept before him, notably Aristotle, who put forward the example of a man equally hungry and thirsty, and Al-Ghazali, who used a man faced with the choice of equally good dates.

The teleological argument (from τέλος, telos, 'end, aim, goal') also known as physico-theological argument, argument from design, or intelligent design argument, is a rational argument for the existence of God or, more generally, that complex functionality in the natural world, which looks designed, is evidence of an intelligent creator. The earliest recorded versions of this argument are associated with Socrates in ancient Greece, although it has been argued that he was taking up an older argument. Later, Plato and Aristotle developed complex approaches to the proposal that the cosmos has an intelligent cause, but it was the Stoics during the Roman era who, under their influence, "developed the battery of creationist arguments broadly known under the label 'The Argument from Design'".

Since the Roman era, various versions of the teleological argument have been associated with the Abrahamic religions. In the Middle Ages, Islamic theologians such as Al-Ghazali used the argument, although it was rejected as unnecessary by Quranic literalists, and as unconvincing by many Islamic philosophers. Later, the teleological argument was accepted by Saint Thomas Aquinas, and included as the fifth of his "Five Ways" of proving the existence of God. In early modern England, clergymen such as William Turner and John Ray were well-known proponents. In the early 18th century, William Derham published his Physico-Theology, which gave his "demonstration of the being and attributes of God from his works of creation". Later, William Paley, in his 1802 Natural Theology or Evidences of the Existence and Attributes of the Deity published a prominent presentation of the design argument with his version of the watchmaker analogy and the first use of the phrase "argument from design".