Al-Ghazzali regards revelation as source of all knowledge. Intellectual enquiry is permissible only as far it is to support the Divine word. Knowledge for any other reason (intellectual curiosity, reward or recognition) is not permissible.

Al-Ghazzali did not believe in causality; he says that it is futile to believe that the world runs according to physical laws. He says it is false to assign a physical cause to any occurence, because it is God who is the cause of all physical events and phenonmena. He constantly intervenes in the world. Consider burning a piece of cotton by fire. It is false to say that fire burns the cotton. According to Ghazzali:

"This we deny, saying: the agent of the burning is God, through His creating the black in the cotton and disconnection of its parts, and it is God who made the cotton burn and made it ashes either through the intermediation of the angels or without intermediation. For fire is a dead body which has no action, and what is the proof that it is the agent. Indeed, the philosophers have no other proof than the observation of the occurence of the burning, when there is contact with fire, but observation proves only a simultaneity, not a causation, and in reality, there is no cause but God."

He contends that mathematics is potentially dangerous, because one may get attracted to other dangerous doctrines which may lead to forsaking belief in revelation.

Irfan, I dont know to what extent you subscribe to Ghazzali's philosophy. With this attitude, you can pretty much rule out science and other fields of enquiry not directly related to religion.