Thus, truth is accompanied by inevitable signs that testify to it, and falsehood is likewise accompanied by inevitable signs that testify to its falsity. It is impermissible to declare an informant truthful—or to brand him a liar—without evidence. Whenever the truth or falsehood of a report, or even its very occurrence, has not been established, one must suspend judgment and say: “I do not know this; it has not been proven to me. I will not assert it, rule on its basis, cite it as evidence, use it as a proof, or build my school, creed, or practice upon it,” and the like.
He must not say, “I categorically pronounce it false and nonexistent,” even though he may be certain that anyone who affirms it is speaking without knowledge; for being sure of the ignorance of the one who asserts something is not the same as being sure that the thing itself does not exist. Whoever makes a categorical claim without conclusive proof, we in turn declare him ignorant, misguided, and mistaken—even if we do not categorically deny the actual existence of what he affirms.
An example is someone who issues a ruling on the basis of the testimony of a discredited, openly sinful witness whose report Allah has commanded us to verify: if he renders a definitive judgment on such a report without evidence establishing its truthfulness, we judge that he has spoken and ruled without knowledge, even though we may not necessarily declare the witness himself a liar.
Similarly, a person is not entitled to deny another’s knowledge or certainty unless he himself is acquainted with the evidentiary grounds by which that other person knows and speaks. Very often someone may possess abundant proofs demonstrating the truthfulness of a particular individual or the reality of a particular matter, while others remain completely unaware of those proofs. This, too, is a mistake into which many people fall: they look only to themselves,