Many later jurists have raised certain questions, claiming that they can be resolved only by the algebraic method of “restoration and reduction.” We have already demonstrated, however, that every juridical matter conveyed by the Messenger—may blessings and peace be upon him—can be answered without recourse to algebra, even though algebra itself is sound. Indeed, both my father and my grandfather—may Allah have mercy on them—were known to have mastered it.

The Islamic law is not contingent on any of their sciences:
We have clarified that neither the Sharīʿah nor the knowledge of it depends in any essential way on disciplines learned from non-Muslims—even when those disciplines are valid. The algebraic method, in fact, merely lengthens the process, and Allah has provided alternative, simpler means, just as we explained with respect to formal logic.

The same applies to everything the Messenger was sent with: determining the direction of the qiblah, establishing the prayer times, recognizing the break of dawn, and sighting the new moon. Each of these can be ascertained by well-known procedures that the Companions and their righteous successors regularly employed; nothing further is required. Many people have since introduced additional techniques, and many of them imagine that one cannot grasp the Sharīʿah without such methods—an idea born of their ignorance.

Knowledge of the qiblah:
Some people even suppose that determining the qiblah is impossible unless one first knows the longitudes and latitudes of the various regions.