§ 49 Ultimate Legal Principles
All rules of law have historical sources. As a matter of fact and history they have their origin somewhere, though we may not know what it is. But not all of them have legal sources. Were this so, it would be necessary for the law to proceed ad infinitum in tracing the descent of its principles. It is requisite that the law should postulate one or more first causes, whose operation is ultimate, and whose authority is underived. In other words there must be found in every legal system certain ultimate principles, from which all others are derived, but which are themselves self-existent. Before there can be any talk of legal sources, there must be already in existence some law which establishes them and gives them their authority. The rule that a man may not ride a bicycle on the footpath may have its source in the by-laws of a municipal council; the rule that these by-laws have the force of law has its source in an act of Parliament. But whence comes the rule that acts of Parliament have the force of law? This is legally ultimate; its source is historical only, not legal. The historians of the constitution know its origin, but lawyers must accept it as self-existent. It is the law because it is the law, and for no other reason that it is possible for the law itself to take notice of. No statute can confer this power upon Parliament, for this would be to assume and act on the very power that is to be conferred. So also the rule that judicial decisions have the force of law is legally ultimate and underived. No statute lays it down. It is certainly recognised by many precedents, but no precedent can confer authority upon precedent. It must first possess authority before it can confer it.
If we inquire as to the number of these ultimate principles, the answer is that a legal system is free to recognise any number of them, but is not bound to recognise more than one. From any one ultimate legal source it is possible for the whole law to be derived, but one such there must be. A statute for example may at any time give statutory authority to the operation of precedent,109 and so reduce it from an ultimate to a derivative source of law.110