In the history of legal thought, various tendencies have emerged in defining the concept of legal validity, according to the adopted criteria. Legal validity has been subjected to axiological, material and formal evaluations as alternatives to each other. Legal validity is reduced to justice (fairness/justness) when evaluated axiologically, to effectiveness (efficacy) when evaluated materially, and to belonging to a certain legal order when evaluated formally. The criteria of justice, effectiveness or belongingness, when taken as alternatives to each other, are not sufficient to define legality (juridicité), that is, to distinguish law from other normative structures, and they also lead to an overlap between the concepts of legality and legal validity. What is just in the natural law doctrine and what is effective in the realist legal doctrine is considered both legal and valid. Positivist legal doctrine, on the other hand, defines legal validity as belonging to a certain legal order, which, in reality, cannot distinguish it from legality. Therefore, legal validity is tried to be comprehended as an additional quality to legality, based on the conditions regarding invalidity. In Islamic jurisprudence, legal validity is accepted as a formal evaluation, not axiological or material. This is a natural and necessary consequence of the principle of shar'iyya, on which the general theory of law is based. Any norm that does not have shar'ī character is not considered valid merely on the grounds that it is just or effective. Determining shar'iyya is a matter of authority and procedure. Tūfī's approach to validity based on maslaha and Ibn Qayyim Jawziyya's approach to validity based on justice, constitute exceptions to the established principle in Islamic jurisprudence. We find a similar exception in the Hanafī approach, which considers the effectiveness of the entire legal order as a condition for the validity of every single norm to be continued. This approach seems to be comparable to the positivist theory, which relates the effectiveness of the legal order as a whole to the validity of norms. In the classical doctrine of Islamic law, an opinion constructed at the theoretical level that a legal norm would lose its validity due to matrūkiyya (desuetudo) was, to the best of our knowledge, defended only by Abū Mansūr Muhammad b. Muhammad al-Samarqandī al-Māturīdī. al-Māturīdī explains his opinion of metrūkiyya as a reason for the invalidity of legal norms on the occasion of the interpretation of the 10th verse of the Sura al-Mumtahina and by taking as evidence the regulations prescribed in the verse, which were annuled by way of desuetudo in time. Desuetudo means that a norm loses its effectiveness. Indeed, al-Māturīdī also defines matrūkiyya as people's abandonment of the norm. al-Māturīdī refers to the invalidation of norms due to matrūkiyya with the term naskh (abrogation), which is used in the classical doctrine of Islamic jurisprudence to mean the invalidation of a norm by the declaration of the Qur'ān or the Sunnah in such a way that it cannot gain validity again. Expressing the concept of invalidity due to matrūkiyya with the term naskh seems to be based on a conscious preference. This is because al-Māturīdī mentions various forms of naskh, and also adds naskh by ijtihād and naskh due to matrūkiyya to the form of naskh, which is almost unanimously accepted in the classical doctrine of Islamic jurisprudence. In al-Māturīdī's theory, although matrūkiyya is a reason for invalidity in terms of legal norms, it is not absolute. The abandonment of the norm, which occurs only under certain conditions, is prescribed as a reason for invalidity, not its mere abandonment. Accordingly, in order for a norm to be considered invalid due to matrūkiyya, the following conditions must occur together for the same norm: a. the absence of a statement in the Kitāb or the Sunnah indicating that the norm is invalidated, b. the rationale (raison d'être) of the norm (the purpose pursued when the norm was legislated) is comprehensible/reasonable (ma'kūl), c. there is an agreement (ijmā) of people to abandon applying the norm or complying with the norm, d. the fact that the norm is about an event with a limited context of social relations (hukm urf: being a special regulation regarding a certain social practice), e. the rationale of the norm has subsequently disappeared. In our opinion, al-Māturīdī's use of the term naskh for the concept of invalidity due to matrūkiyya implies that the relevant norm will not be valid again. For, he considers invalidity due to matrūkiyya to be possible only for norms that regulate events with a limited context of social relations, which confirms the conclusion we have drawn when taken in the sense of norms that are about events that will no longer take place in social life after their disappearance. In al-Māturīdī's theory, naskh due to matrūkiyya represents, in our opinion, a different form of realization of invalidity that cannot be reduced to naskh by ijtihād. Naskh by ijtihād means deciding on the invalidity of a norm through a process open to preference due to the disappearance of the rationale for its legislation over time. Although the norm is still applicable to the social relationship it is about, it is considered invalid because it no longer fulfills the rationale, for which it was legislated. However, naskh due to matrūkiyya is a purely factual type of invalidity. Not only the rationale for which the norm was legislated, but also the context of the social relationship has disappeared.