when denying that something is obligatory or prohibited. This, by universal agreement, is the weakest form of evidence, and all agree that it may be resorted to only after a thorough investigation into whether any evidence in the revealed law establishes an obligation or prohibition.

Some do not permit reliance on it to deny a ruling, but only to rebut an opponent and challenge his claim. Such a person says: “I neither affirm nor deny the obligation. Rather, I demand evidence from whoever affirms it, or challenge his claim, or rebut his attempt to establish an obligation without evidence.” This is the position taken by some followers of Abū Hanīfah. As for the literalists, it is their principal basis of argument, but only after investigating the evidence of the revealed law.

It is impermissible to assert that things are absent or nonexistent merely on the basis of this presumption of continuity, without adducing evidence that entails their nonexistence. Whoever does so is speaking falsely and without knowledge, for many things exist in the world of which a person knows nothing. His lack of knowledge is not knowledge of nonexistence. Nor does the mere presumption that events have not occurred yield knowledge that any particular event has not occurred, unless there is evidence establishing its nonoccurrence.

The presumption of continuity is, however, used to tip the balance when evidence conflicts. Any evidence establishing that something has occurred outweighs the mere presumption that it has not. This is the correct conclusion that the person praying is instructed to seek through considered judgment: any evidence indicating that he has prayed four units outweighs the presumption that he has not performed the prayer. This is the essence of the issue.