He said:

“The signs of the Creator’s workmanship—exalted is His power—in existing things are more abundant and more evident than any other proof. Whoever recognizes the signs of His workmanship by the light of reason comes to know that the Maker exists. For nothing made can be conceived without a maker, nor anything created without a creator.”

He said:

“The proof that rational inquiry is the first obligation is that all other obligations, such as prayer and fasting, can be fulfilled only after knowledge, since only someone who knows Allah can validly seek nearness to Him. Knowledge therefore precedes all other obligations, while rational inquiry precedes knowledge, because it is the means to it, and the means to something precedes it. Thus, rational inquiry precedes everything obligatory. Here, however, its precedence concerns its occurrence, not its obligatory status; otherwise, the first obligation is knowledge—that is, the obligation intended in its own right.”

He said:

“What makes rational inquiry necessary is that there is no path to knowledge except through it. The proof is that knowledge either arises immediately, as when a rational person knows that ten is greater than five, or is acquired through a means, as with our knowledge of perceptible things when we perceive them through our five senses, and our knowledge of things absent from us when a vast multitude who witnessed them informs us of them, such as our knowledge