Book excerpt: Using contemporary illustrations, Legal Maxims in Islamic Criminal Law delves into the theoretical and practical studies of al-Qawaid al-Fiqhiyyah in Islamic legal theory. It elucidates the importance of this concept in the application of Islamic law and demonstrates how the concept relates to the objectives of Islamic law (maqāṣid al-Sharī‘ah), generally. Included in this examination are the following maxims: al-Umūr bi-Maqāṣidihā ("Matters shall be Judged by their Objectives"); al-Yaqīn lā Yazūl bi-sh-Shakk ("Certainty Cannot be Overruled by Doubt"); al-Mashaqqa Tajlib at-Taysīr ("Hardship begets Facility"); Lā Ḍarar wa-lā Ḍirār ("No Injury or Harm shall be Inflicted or Reciprocated"); and al-ʿĀda Muḥakkama ("Custom is Authoritative").