Al-Ghazali was a theologist who studied the philosopher's of his time and looked at how there works were compatible with Muslim beliefs, but upon studying them, he realised that there was a limit to obtaining knowledge from rational methods and quickly became disappointed with their work. In order for their works to be compatible with Islam in regard of Neo-Platonism, he set out to expose their weaknesses of philosophy.
During his time, theology was in a weak position as it was unable to answer to philosophical criticisms and Al-Ghazali set forth to show why the philosophers made so may errors in their metaphysics. Two chief concerns of his were philosopher's Al-Farabi and Ibn Sina (also known as Avicenna), their views were unacceptable in Islam and Ghazali ended up producing his most famous work known as the 'Inconsistency of the Philosophers (Tahafut)', demonstrability underpinned the most of this and brought to light the weaknesses of the philosophers views. It consisted of 20 points of doctrine, 3 of which were deemed serious mistakes and contradictions made by the philosophers that amounted to unbelief, the contradictions of which arose from principles that are key to Muslim life. In Ghazali's words the books aim was to do just this, 'â€¦to show your inability to make good your claims to knowledge of the truth of things by apodictic prods, and to make you doubtful of your claims' (Watt, 1963, 58).
To understand Al-Ghazali's criticisms it is important to know why he did so and what he thought was so wrong with the philosopher's of his time producing these supposed metaphysical errors which contradicted Muslim beliefs. His main targets were as mentioned Al-Farabi and Ibn Sina, whom were Muslim's themselves and were exponents of Aristotle's philosophical thoughts and ideas. Such works contravened Islam's religious beliefs and Ghazali regarded those who deviated from ones own system of doctrine in Islam as infidels and corrupt. Furthermore, he wanted to put much emphasis on the fact that their books were no good and any reference made to them was to be avoided because you were too also considered as a liar by believing their philosophical ways which refer to very religious works and off them, base their arguments and cause deception and falsehood which denied prophecy and corrupted Islamic faith.
Ghazali believed that only if the philosophers' works were supported by solid proof to back up their theories, and they did not end up contradicting the Qur'an and Sunnah, then only then, is it deemed ok to use them as a reference. . He wanted to resolve any tension between theology and philosophy so that he could see if any truth lay in the philosopher's works and all he could do was show what had to be rejected from their theories and what could be valuable to Islamic theology
However, when Ghazali set out to show their weaknesses it became more apparent that their work was no good in any respect, the Tahafut only refuted their work and did not defend any theological doctrine, as this was not what was important, 'The incoherence of [the philosophers] beliefs and the contradiction of their metaphysical statements, relating at the same time their doctrine as it actually is, so as to make it clear to those who embrace unbelief in God through imitation that all the significant thinkers, past and present, agree in believing God and the last day' (Marmura, 2000, xxii).
The philosophers in question were regarded as pseudo-intellectuals of their era and their main influences had been Plato, Aristotle and Socrates. Al-Farabi and Ibn Sina's philosophical works were Aristotelian and Neo-Platonic thoughts and ideas to which they have used most of their works to rationalize their disregard for obligations from the religious law of Islam. Ghazali singles them out, and when looking at the inconsistencies of the philosophers he was directing criticism at all but mainly Ibn Sina's works. They usually supported their theories with quotes from the Qur'an and ended up meddling with many holy books, which resulted in producing false claims about Islam and its place with philosophy. They both opted for unbelief and had no real knowledge of what their thoughts were or how their thoughts were useful to philosophy in their time, they just imitated other philosophers and ended up failing to demonstrate properly their theories and were unable to prove religious truths from any theory.
Al-Ghazali wanted to focus on these errors and show exactly why their theories were inconsistent, he outlined his main criticisms and they consisted of twenty theses. Seven doctrines held by philosophers cannot be demonstrated by reason, which was one of the main arguments from the philosophers works, for Ghazali reason isn't enough to prove the world has a start or a creator, it is not sufficient in philosophy and they fail to be free from being inconsistent. The other thirteen points fall into three groups and these were of Ibn Sina's theories which were condemnation as disbelief: The first and largest group is the world everlasting and having no beginning, the second is that God only knows universal and not particulars and he has no attributes and lastly that there is no resurrection of the body. Taylor and Adamson detail exactly what these 3 points involve, 'â€¦Denial of bodily resurrection, which is entailed by Avicenna's thesis that after the body's death, only the soul survives; the denial of God's knowledge of particular things, which is entailed by Avicenna's thesis that God knows particulars only in a universal way; and the denial of the world's temporal originatedness, which is entailed by Avicenna's thesis that the world, though, caused by God, is co external with him.' (Taylor & Adamson, 2005, 104-105). From this we see exactly what Ghazli deemed as his chief criticisms of the philosophers and in particular, Ibn Sina's works and how they created falsity of Islamic religious beliefs.
The first criticism was Pre-Eternity and was the largest in the book and named as, 'On refuting their doctrine of the world's past eternity' (Marmura, 2000, 12). This was central to the nature of divine causality and the philosophers believed that, 'The world is the necessitated effect of an eternally necessitating cause and hence must be external' (Marmura, 2000, xx).
They saw no reason to believe that you would think something, which no one knows to be possible as having divine power. It is impossible for the world to be impossible originally then become possible, existence of the world must be possible before its existence, and possibility has no beginning. If the world was created in time it means that there would be a delay of a necessary cause such as God, since there is no other reason to explain the delay. As long as the world has existed and its origin in time is impossible, past eternity is already necessarily established. They claimed that it was impossible for God to choose any time for creation to occur it was just not possible.
Ghazali found a reason to deny this view, "the non existence that precedes the world [terminating with] the first limit of [the world's] existence is essential' (Marmura, 2000, 34). God exists without the world, as he is the divine will, which wills everything else. Creation was just decided in the eternal past long before the world came into existence so any change in God does not matter, as he created time and he has the power to choose a particular time for the world to exist. He believed that the world was brought into existence at a finite moment in the past from eternal divine will which is God as the creator, 'Objection before the world existed, the willer existed and will existed, the creator is prior in time to the world before time and existence. Creator preceded world by a long time before, 'non existence precedes existence'' (Marmura, 2000, 31). For Ibn Sina, this raised the question of whether God acts by necessity of his nature or if it is just a voluntary act? If this was the case, it means that we must deny the attribute of will, which is meant to be a divine attribute, and to Ghazali this was the main problem of Ibn Sina.
The philosophers would have to come up with a way to prove how the world ended up being created in a time of eternal will and Ghazali points out again that they fail to do just that. There is no demonstration of how they came to their conclusion that the world existed without God's existence and the philosophers have no way of demonstrating further the world being impossible to have existed.
The next criticism of Ghazali was the thirteenth doctrine, 'On refuting their statement that God, may He be exalted above what they say, does not know the particulars divisible in terms of temporal division into what is, what was, and what will be' (Marmura, 2000, 134). This was Ibn Sina's view that God only knew particulars in a universal manner and was only able to make distinctions between particulars that were celestial or terrestrial, although Ghazali does not explicitly expose this.
The sun is regarded as a celestial particular since there is only one of its kind, the only one its existence and is one of a kind and God is able to know its particulars as there is not one member which is like it. Terrestrial however is not one of its own, just as humans individuals acts are not seen as being so according to Ibn Sina. He criticized God by claiming that he could not know everyone's particulars as there were too many and if this is so, how could God know any individuals states or acts in the same way he understands the celestial particulars. Ibn Sina comes to the conclusion that God is therefore simple and has no attributes himself that are distinct from his essence, and he then has no definite character.
Al-Ghazali points out a critique of this, and this is that there is no way Ibn Sina could know such a thing or guess at. His theory just contradicts the Qur'ans assertions that the divine entails omniscience and there is no way one could deny God's knowledge of everything that exists if he created everything originally. The philosophers deny God's ability to know particulars, and link this knowledge with particulars and this inability, which is claimed, changes God's essence. Ghazali denies this though, because if God created each person from birth and decides when one dies as written in holy books, then his knowledge of us would not change even if it was the case each day he had to know more particulars. God would understand all and does not have a limit to distinguishing between only celestial and terrestrial particulars.
The final chief criticism made by Al-Ghazali was the twentieth doctrine which involved Ibn Sina's denial of the soul and bodily resurrection and was named as, 'On refuting their denial of bodily resurrection and the return of spirits to bodies; of the existence of corporeal fire; of the existence of paradise, the wide eyed houris, and the rest of the things that people have been promised; of their statement that all those things are parables made for the commonality to explain spiritual reward and punishment that are of a higher rank than the corporeal' (Marmura, 2000, 208).
The philosophers denied resurrection of any bodies pleasure in paradise and torments in fire, and moreover the complete denial of paradise existing. Ibn Sina's main claim was that God does not have the power or ability to will over all things. This was seen as a shocking theory to be put forward, in Islam it has always been stated that God brings about ones resurrection and afterlife and anything he willed he would enact. However, for philosophers, God isn't capable of willing or acting in his own accord and certainly he was not capable of doing so for every individual (this argument was also seen in particulars, number 13). They adopted a dualistic outlook of the soul being the person and the body being a house for its own soul, and the body is just as much the person as the soul.
Ghazali denied this, and believed that when God creates 'x' he creates 'y', He is the direct cause of both birth and death and only he can change this at any time and resurrect us like a second creation. The event of each person's creation naturally works with the event of death eventually and we cannot guarantee or decide whether or not the things that have been promised in the Qur'an will or will not occur. The philosopher's theory had no evidence of the soul's immateriality and maintained further that even with the soul being immaterial, resurrections of the body could still occur. When stated in the Qur'an about bodily resurrection, it was not places there to be taken lightly it is explicit in what it says and wants to portray and should be taken literally and accepted in Islam.
The soul for Muslims, endures everlasting life after the bodies death of either pleasure in paradise of pain in fire. This was all down to ones soul and how pure it was; through life intellectual pleasures are seen as most important rather than bodily ones.
After Al-Ghazali set out to bring to light the philosophers weaknesses, his works ended up getting negative results but he significantly weakened the philosophical movement after producing his book, and in this light succeeded in showing the falsity of philosophers metaphysical theories. No philosophical works emerged after his time in the east and it is believed that he could have caused it ceasing to exist, "â€¦his attack on the philosophers had been so devastating that philosophy was killed offâ€¦'(Watt, 1985, 91). However, there was no evidence to justify that this was so, but Ghazali definitely transformed philosophical theories and individual's ideas and thoughts towards it. He ended up being seen as one of the greatest Muslims of his time after Mohammed (PBUH), which was all down to the victory of theology showing philosophers up as infidels and irreligious men. Ghazali judged Sufism as the best doctrine over both philosophy and theology because it leads to a positive knowledge of God.