Pacta sunt servanda - Agreements must be kept. Contracts are the law or contracts establish obligations (between those who sign them).⏎
Nullum crimen, nulla poena sine praevia lege poenali - There can be neither crime nor punishment unless there is a penal law first.⏎
Prior tempore potior iure - "Earlier in time, stronger in law". A legal principle that older laws take precedence over newer ones. Another name for this principle is lex posterior.⏎
Qui facit per alium facit per se - "Who acts through another, acts himself." One who delegates a task to another, takes full responsibility for the performance of that act as if he himself had done it. Basis for the law of agency.⏎