Abu Hamid Ibn Muhammad Ibn Muhammad al-Tusi al-Shafi’i al-Ghazali had some interesting things to say, "Concerning the Natural Sciences," towards the end of his work, "The Incoherence of the Philosophers." He attempts to prove, by use of logic and sacred texts, the impossibility of any necessary causal relationship between two substances, be they animate or inanimate. I attempted to outline his arguments on my overview page, and I will now attempt to give arguments to justify my own evaluation of his work.
It is difficult to approach the text as a modern agnostic reader, as it was designed specifically addressing other Muslim thinkers of al-Ghazali's time. Al-Ghazali's primary concern was refuting the claims of other Muslim thinkers, and, as a result, many of his points and proofs, are either dependant upon, or adressing sacred texts. This does not, however, rob the work of any pertinence. On the contrary, I found it fascinating that an ultra-religious Sufi living in the 11th and 12th centuries would have crafted such meticulous logical arguments on the topic of causation. I was even more fascinated, however, at his conclusion--that we can attribute no "effects" to any direct, necessary "cause," other than God (or his agents). I thought that idea wasn't formulated until a white guy named Hume, centuries later, decided to tackle the issue after a trip to a pool hall.
Al-Ghazali wrote that "the affirmation of [a cause or effect] does not imply the affirmation of the other; nor does the denial of [a cause or effect] imply the denial of the other." There is nothing in the actual world sufficient enough to convince al-Ghazali that there is anything more than a usual concurrance between what is deemed "cause" and "effect." Al-Ghazali postulates that everything (and this covers all objects, actions, etc.) is brought into being by the "First One." However, if we remove the Islamic elements from the first section, we find a man who questions causal necessity, and who can offer no suitable alternative, that does not involve an issue of faith. In short, Al-Ghazali would believe in the impossibility of proving the necessity of causation, even if God were to never enter the equation. God is supplied as an alternative, but without him, we are still left with al-Ghazali's negation of temporal causality. I think that this is very important to keep in mind.
Al-Ghazali proceeds to address further potential arguments that may be raised in response to his propositions. His theoretical opponent might raise the question that I raised upon first being introduced to Hume: how can we know anything for certain? He suggests that someone might take him to mean that, coming upon a man in the market, it could never be certain that he was "born...[rather than being] one of the fruits in the market which was changed into a man and he is that man." I have a problem with al-Ghazali's response to this question: that "God has created within us knowledge that he will not bring about everything that is possible." I would have been more satisfied if he had simply suggested that we simply play the odds and hope that God doesn't decide to bring about something that is so unusual as, say, stopping the motion of the Earth, or changing all oxygen to carbon. But, since he's a devout Muslim, I suppose that the answer he gives is a bit more consistent, and must be allowed for.
Here, al-Ghazali moves on into a rather long discussion of the magnitude and nature of miracles, which honestly seems to be of little or no interest to the modern reader. What brings about the passage is his claim that, perhaps, there is something inherent in fire that predisposes the fire to accept from God the act of burning another substance. But he still allows for God to decide against a specific item (like Abraham) from being burned by a specific fire. In essence, al-Ghazali is saying that, in the observable world, the laws of causation generally apply, but only because it is God's will that it do so. So, backed into a corner, he really is saying that causation is the norm, and anything that does not adhere to the excepted patterns of causation is simply a miracle. He does qualify this, however, by stating that "the predispositions for receiving forms varies through causes hidden from us, and it is not within the power of flesh to know them." As far as I can tell, this reflects al-Ghazali's true beliefs, and his preceding concessions to his opponents are little more than a watering down of his real focus, in order to seem a bit less revolutionary. This strikes me as a bit odd, since in many ways, a revolution is exactly what al-Ghazali, as a Sufi, desired. Perhaps this is the recessed academic in him, putting in his own two cents.
The final point of interest that I found in the excerpt addressed the nature of the impossible. It might sound heretic for a fundamentalist Sufi to propose that anything is impossible for God, but his reasoning on this topic is unassailable: he simply illustrates that the impossible is, definitionally, not possible, even for an omnipotent force. The most illustrative example is the one that addresses the impossibility of God changing an object or being's "genera," a notion that seems to have been supported by "some of the Mutakallimun." Now, I couldn't tell you what a Mutakallimun is, but al-Ghazali makes them seem pretty stupid. He makes the point that "if, for example, blackness is changed into power, blackness would remain or not remain. If it ceases to exist, it would not be changed, but it would not exist anymore, and something else would exist [in its place]." This sounds odd, but it makes some odd kind of sense. Most of what I've read makes sense. All things considered, al-Ghazali earns himself an A-.