Does a ruling become void if its cause becomes void, such as the permissibility of drinking alcohol if it is not intoxicating, or the permissibility of a woman traveling without a mahram if she is completely safe from temptation?

The jurisprudential principle "A ruling revolves with its illah (effective cause) in existence and non-existence" means that a legal ruling exists when its illah is present and ceases to exist when its illah is absent. This is known as ṭard (concomitance) and aks (contra-concomitance) in Uṣūl (principles of Islamic jurisprudence), and it is one of the rules of qiyās (analogy) upon which jurists have based many rulings. The application of this principle has conditions, including: that the illah be a transitive, apparent, well-defined, and appropriate attribute for the ruling, free from contradicting a text or consensus, and consistent (muṭṭarid). The same ruling might exist due to two different ilal, or independently of an illah. This deduction is the task of the mujtahid (independent jurist) scholars.