Proof of the Truthful
Furthermore, through a series of arguments, he derived that the necessary existent must have attributes that he identified with God in Islam, including unity, simplicity, immateriality, intellect, power, generosity, and goodness.
The most concise and influential form is found in the fourth "class" of his Remarks and Admonitions (Al-isharat wa al-tanbihat).
[12][13] Avicenna argues that this aggregate, too, must obey the rule that applies to a single contingent thing; in other words, it must have something outside itself that causes it to exist.
[5] Avicenna is aware of this limitation, and his works contain numerous arguments to show the necessary existent must have the attributes associated with God identified in Islam.
[14] For example, Avicenna gives a philosophical justification for the Islamic doctrine of tawhid (oneness of God) by showing the uniqueness and simplicity of the necessary existent.
[17] Avicenna derives other attributes of the necessary existent in multiple texts in order to justify its identification with God.
[5] He shows that the necessary existent must also be immaterial,[5] intellective,[18] powerful,[5] generous,[5] of pure good (khayr mahd),[19] willful (irada),[20] "wealthy" or "sufficient" (ghani),[21] and self-subsistent (qayyum),[22] among other qualities.
[4] The phrase wajib al-wujud (necessary existent) became widely used to refer to God, even in the works of Avicenna's staunch critics, a sign of the proof's influence.
Averroes, an avid Aristotelian, argued that God's existence has to be shown on the basis of the natural world, as Aristotle had done.
[26] Other Muslim philosophers such as Al-Ghazali (1058–1111) attacked the argument over its implications that seemed incompatible with God as known through the Islamic revelation.
[27] He further argued that God's free choice can be shown by the arbitrary nature of the exact size of the universe or the time of its creation.
He pointed out that Avicenna adopts a piecemeal approach to prove the necessary existent, and then derives God's traditional attributes from it one at a time.
[26] German philosopher Immanuel Kant (1724–1804) divided arguments for the existence of God into three groups: ontological, cosmological, or teleological.
[5][25][28] Scholars Herbert A. Davidson, Lenn E. Goodman, Michael E. Marmura, M. Saeed Sheikh, and Soheil Afnan argued that it was cosmological.
[29] Others, including Parviz Morewedge, Gary Legenhausen, Abdel Rahman Badawi, Miguel Cruz Hernández, and M. M. Sharif, argued that Avicenna's argument was ontological.
