No one doubts the existence of positive law (hereafter PL), but we wonder about its rightness. No one doubts the rightness of natural law (hereafter NL), but many wonder if it actually exists. PL exists even when unjust, but for NL to exist it is not enough to be just. One way of comparison between them may be articulating the notion of the existence of law or its being in force. Being in force of the intrinsic value per se, i.e. in virtue of its moral merits, has been distinguished from being in force as formal validity and from being in force as factual existence. But this is not very convincing, because a norm that was valid only axiologically and was not part of a normative system in some way effective would be pure and simple morality and nothing else. Law, unlike morality, requires some degree of factual existence. One of the few cases of “existence” of NL that we know of is the Nuremberg Tribunal, which condemned Nazi leaders for having obeyed unjust positive laws, i.e., for having violated NL though obeying PL, according to Radbruch’s Formula which states that where statutory law is intolerably incompatible with the requirements of justice, statutory law must be disregarded in favour of justice (Radbruch 19565, 345).
The essential requisites of NL do not include factual existence and so it is not “law” in the narrow sense (Verdross 1958, 252). However, we may wonder whether effectiveness and formal validity are all that it is required for there to be “a legal system ” and whether perhaps it is not also necessary a certain correspondence to criteria of justice, at least as regards the legal system as a whole (Alexy 1992). If it is felt that PL as a whole, in addition to being effective, must at least satisfy minimum needs for justice, then the problem of the relation between PL and NL really arises, but within PL itself. Hence the question needs to be formulated as follows: what role is played by values