one or two people in arithmetic; but when their numbers grow large, errors that were possible for an individual become impossible. We know self-evidently that two people together possess more knowledge than either one alone, and that their combined strength exceeds that of either individual. Thus, the occurrence of error among individuals does not entail its occurrence among large numbers.
Allah Most High says:
“so that if one of them errs, the other can remind her” [Surah al-Baqarah: 282].
In arithmetic, one person may make a mistake while a group does not. The same applies to the crescent moon: an individual may think something is a crescent when it is not, whereas such an error is inconceivable among a large number of people.
We know that when Muslims come together in large numbers, their impulse toward shameful deeds and injustice is weaker than when they are few. When gathered together, they do not collectively agree to violate the laws of Islam as one or two individuals might do. Social and civic life are possible only under a just legal order. The inhabitants of a city cannot agree to permit unrestricted injustice against one another, for life would be impossible under such conditions. Indeed, we find that when a ruler wrongs some of his subjects, some of his associates must remain free from such injustice while he wrongs the subjects. When they are all on an equal footing [in a matter] (1), none of them wrongs another. It is well known that the whole may be subject to a different judgment from its individual parts, whether it comprises entities or attributes.
Among the illustrative examples that a leader gives his followers is that a single arrow (2)