does not involve any recommendation to perform its actions twice or three times, unlike ablution. Tayammum differs from ablution in several aspects of its form, but has the same legal effect, because it is a substitute for it. It must therefore take its place, as all substitutes do. This is what the revealed text and analogy require.

If it is said, “Ablution removes ritual impurity, whereas tayammum does not,” there are two answers.

First, whether tayammum removes ritual impurity or not, the Lawgiver has made it a means of purification that takes the place of water when water is unavailable. It must therefore carry the same rulings of purification as water, unless evidence from Islamic law establishes otherwise.

The second answer is that saying tayammum removes ritual impurity or does not remove it involves no disagreement over practice; the disagreement is merely conceptual and terminological. Those who say that it does not remove ritual impurity argue that, if it did, a person would not need to renew his purification upon becoming able to use water. Yet the revealed text and scholarly consensus establish that tayammum is invalidated by the ability to use water.

Those who say that it removes ritual impurity mean only that it removes it temporarily, until the person becomes able to use water. Thus, they do not disagree over any practical ruling of Islamic law. Rather, their disagreement goes back to a principle of legal theory concerning the question of exceptions to an effective cause, and whether