menstrual refuse, dog flesh and foul-smelling matter?” He replied, “Water is purifying; nothing renders it impure.” He thus denied that it was impure because this needed clarification, just as he denied that it entered a state of major ritual impurity because that needed clarification. Allah, Glorified is He, has permitted wholesome things for us and forbidden foul things. Impurities are among foul things, so when water is altered by an impurity, using it becomes forbidden, because that constitutes using something foul.

This rests on a fundamental question: when an impurity falls into a large quantity of water, does analogical reasoning require that the water be deemed impure because the lawful has mixed with the unlawful, unless evidence establishes its purity? Or does analogical reasoning require that it remain pure until the foul impurity whose use is forbidden becomes perceptible in it?

The jurists among Ahmad’s followers and others hold two views on this principle. The first holds that impurity is the default ruling. This is the position of Abū Hanīfah’s followers and those among the followers of al-Shāfiʿī and Ahmad who agree with them, on the grounds that mixing the lawful with the unlawful makes both forbidden.

Abū Hanīfah’s followers then applied this principle consistently to water in which movement at one end causes movement at the other. They said, “The impurity reaches wherever the movement reaches.” They could not extend this principle to quantities greater than that, since doing so would require deeming the sea impure, whereas nothing renders the sea impure, according to explicit scriptural evidence and scholarly consensus. Nor did they apply this principle consistently in cases where