they have stated, namely that when a person supports what he knows with evidence of a kind that cannot be invalidated, and his confidence in what he acknowledges has become firmly established over his lifetime, with that knowledge suffering neither corruption nor deficiency, and those equal to him in knowledge, as well as those surpassing him in learning and scholarly inquiry, agree upon it, his confidence in it is firmly established on two grounds:

First, his own knowledge and experience.
Second, the agreement of the people of the faith concerning its soundness.

No doubt can challenge something of this kind so as to deprive the person who holds to it of his confidence. For it is firmly established among ordinary people generally, without disagreement among them, that every constructed, composite body has been brought into existence after not existing. Its dismantling can be conceived just as its construction is recognized, although none of them is its own maker, nor was it made by another like it. They also recognize that an agent must precede what it produces. Since bodies are alike in this respect, this indicates that their maker is other than they are: one who does not share the characteristic that renders them powerless. This is plain and clear; it cannot be denied, nor can any specious doubt challenge it in a way that affects what is firmly established in the mind of the person who knows it.

This is sufficient: no ordinary person falls short of grasping it, and no scholar can add anything to it except by improving its formulation or eliminating grounds for specious doubts about it.

This goes beyond simply understanding it and being confident of its soundness. Hence it is one of the communal obligations.”