The five rulings

The ahkam al-khamsa, the five rulings, are the categories into which Islamic jurisprudence sorts every human act. Fard or wajib is obligatory: rewarded when done, punishable when omitted. Mustahabb, also called mandub or sunna, is recommended: rewarded when done, not punished when left. Mubah is permitted and indifferent, carrying neither reward nor blame. Makruh is disliked: better avoided, but not punished. Haram is forbidden: punishable when done, and rewarded when abstained from for God's sake.

The scheme's most consequential feature is the size of its middle. Most of ordinary life falls under mubah, and the jurists' working presumption in transactions and customs is permission unless a text establishes otherwise, which is why Islamic law expanded readily into commercial forms that no scripture mentions.

The Hanafi school alone divides the obligatory in two. Fard rests on certain evidence, the Qur'an or mass-transmitted report, and its denial is unbelief; wajib rests on probable evidence such as a single-chain report, and its neglect is sin but its denial is not unbelief. The standard example is the witr prayer, obligatory for Hanafis in the second sense and strongly recommended for the other schools. Hanafis likewise split the disliked into makruh tahriman, close to the forbidden, and makruh tanzihan, merely unbecoming. The other three Sunni schools treat obligatory as one category, and the difference is a good illustration of how a school's theory of evidence reappears as a difference in its vocabulary.

The five-ruling scheme's durability rests on its capacity to absorb entirely novel questions the classical jurists never anticipated, and looking at how contemporary scholars have sorted a few modern cases shows the framework still doing live interpretive work.

Smoking became contested only after tobacco reached the Muslim world, and rulings shifted as medical knowledge changed: early jurists, lacking evidence of harm, often placed it at makruh or mubah; as evidence accumulated, modern fatwa councils moved it toward haram, reasoning from the principle that deliberately harming oneself is forbidden, while others retain makruh, on the ground that the harm is not certain enough to meet the stricter evidentiary threshold haram usually requires.

Cryptocurrency shows the scheme handling a question with no premodern analogue: fatwa councils split between treating it as legitimate property (mal), generally mubah subject to the ordinary rules against fraud and excessive uncertainty (gharar), and treating its volatility and lack of backing as itself a form of gharar severe enough to move it toward haram or makruh, with rulings varying by jurisdiction and instrument.

Organ donation shows the scheme resolving toward near-consensus: early hesitation over the sanctity of the body has given way, in most contemporary fatwa councils including Al-Azhar, to permitting or recommending donation as mustahabb, an act of lifesaving charity, on the ground that preserving another's life outweighs the classical concern for bodily integrity after death.