The principle of nulla poena sine lege, insofar as it applies to general criminal law, is enshrined in several national constitutions and international instruments (see Article 7, paragraph 1, of the European Convention on Human Rights). However, when applied to international criminal law and international humanitarian law, the same instruments often allow for the ex post application of the law. For example, murder is still a common law offence and has no legal definition. The Homicide Act of 1957 did not contain a legal definition of murder (or any other homicide). Thus, over the next 40 years, the definition of murder was the subject of no fewer than six appeals to the House of Lords (Director of Public Prosecutions v. Smith  A.C. 290; Hyam v. Director of the Public Prosecutor`s Office  A.C. 55; Regina v. Cunningham  A.C. 566; Regina v.
Moloney  A.C. 905; Regina v. Hancock  A.C. 455; Regina v. Woollin  4 A11 E.R. 103 (H.L.)). Traditional meaning of nullus, nullum in English (with legal use of this Latin concept in England and the United States in the nineteenth century) : (in Latin) Nobody; nothing; zero; Empty. Nulla bona (no goods): Return of a sheriff to a fieri facias if the defendant had no goods in the county on which tax could be levied. Nulla pactione effici potest ut dolus praestetur (no agreement can lead to fraud): No possible contract can prevent the nullity of the contract by fraud. Nullius filius: son of nobody; One.
Nullius in bonis: nobody`s property. Nullius juris: without legal force. Nullum arbitrium: no arbitral award; see NULL AGARD. Nullum iniquum est praesumendum in jure: Legally, nothing unjust can be assumed. Nullum simile is idem: nothing like this is the same. Nullum tempus occurrit regi (no time runs against the king): No passage of time is a bar to the right of the crown. Nullus commodum capere potest de injuria sua propria: No one can exploit his own wrong. Nullus idoneus testis in re sua intelligitur: No one is considered an appropriate witness in his own case. Nullus jus alienum forisfacere potest: No one can lose the right of another.
Nullus recedat e curia cancellaria sine remedio: No one may leave the Court of Chancery without appeal. Nullus videtur dolo facere qui suo jure utitur: He should not be considered a wrongdoer exercising his legal rights. The legal principle nulla poena sine lege as a principle of natural law is based on the scholastics` assertion of the preconditions of a guilty conscience. Referring to Jerome`s commentary on Ezekiel, Thomas Aquinas and Francisco Suárez analyzed the formal conditions of the punishment of conscience. Thomas located the conditions in synderesis.  For him, it is a formal and active part of the human soul. An understanding of activity that corresponds to human nature is formally possible due to synderesis. Therefore, synderesis in the works of patristic authors contains a law that prescribes how man should act as a human being.  In individual cases, the content of this law is determined. For the scholastic, this is evident in the effect of the intellect. This action is named after Thomas conscientia.  A possible content of conscientia is punishment in accordance with the content of synderesis if man has not acted in accordance with human nature.
An example of punishment is madness, which has been a punishment of conscience since ancient times. Oresteia is a famous example. Nullum crimen sine lege is sometimes called the principle of legality. It is also interchangeable with «nullum poena sine lege», which translates to «no punishment without law». However, some jurists criticize this because in the legal systems of continental Europe, where the maxim was first developed, «criminal law» was generally understood as statutory criminal law in order to provide the individual, considered a fundamental right, with a guarantee that he will not be prosecuted for an act or omission that is not considered a crime under the laws adopted by the legislators in force. then. the act or omission and only the penalties in force at the time of the offence are applied. [ref. Even bearing in mind that certain acts are prohibited by general principles of international law, critics point out that a prohibition in a general principle does not constitute justification for a crime and that the rules of international law do not provide for specific sanctions for violations. Nulla poena sine lege (Latin for «no punishment without law», anglicized pronunciation: /ˈnʌlə ˈpiːnə ˈsaɪniː ˈliːdʒiː/ NUH-lə PEE-nə SY-nee LEE-jee) is a legal principle that states that one cannot be punished for something that is not prohibited by law.
This principle is accepted and codified in modern democratic states as a prerequisite for the rule of law.  It has been described as «one of the most widespread value judgments in the entire history of human thought.»  For more information on nullum crimen sine lege, see this article on the Statute Law Review, this article in the Journal of International Criminal Justice, and this article in the Georgetown Law Journal. Nullum crimen sine lege is the principle of criminal law and international criminal law according to which a person cannot or should not be punished criminally, except for an act that was criminalized by law before the act. This idea is also reflected in laws that require crimes to be published in a clear legal text. One of the complexities is the legislative power of judges under the common law. Even in civil law systems that do not allow judicial law, it is not always clear when the function of interpreting criminal law ends and when judicial legislation begins.