The positive problem is very obvious in the acquisition of scientific knowledge. Let us look at the contention of the logical positivists who hold that for a proposition to be true or meaningful, it must in principle be verifiable. The key word here is verifying of verification. The critical question we must ask ourselves is how we verify such metaphysical statements, as "God exists “God does not exist” or that the universe is one vast mind, or that the world of forms is real”?. These metaphysical statements under the arrangement of the critics are meaningless and nonsensical statements because they are not verifiable in principle. The problem is that the thesis of logical positivism, which holds that for a proposition to be true or meaningful, it has to be verifiable in principle, in Unah"s opinion, is itself not verifiable. This has in fact generated unending debate among philosophers.
In this vein therefore, Hart's concept of law has also been dealt with a colossal blow by the legal philosophers. His rules recognition, according to some legal philosophers, did not pass the severe test of clarify neither did it tell us how to ascertain those rules.
To start with, Hart's analysis of the concept of law is divided into two types of rules, namely, primary and secondary rules. According to Hart, the secondary rules cover, inter alia, what he calls rules of recognition”. These rules provide authoritative criteria f or identifying primary and other secondary rules and are often referred to as “norms of competence”.
The question Critics ask is “How then are these rules of recognition to be ascertained? Hart point out that such rules are often not expressly stated, but can be shown by the way in which particular primary rules are identified by the courts and other legal officials. But critics disagree with Hart and maintained that Hart is ambiguous as to whether in every legal system there can be only one rule of recognition and also whether it is duty-imposing or not.
Hacker in his book Law, morality and society, asserts that Hart stipulates our rule only, which imposes a duty upon judicial to exercise their adjudicative power by applying laws satisfying certain criteria. Hacker argues however that there may be several distinct rules of recognition addressed to different judicial organs and that Hart missed the point he intended to explain.
R. Sartorius criticized Hart on the rules of recognition and claims that it is a rule of positive law. Harris describes such rules as a social phenomenon. But if according to Hart it is to be regarded solely as a fact, then Hart would seen to be guilty of deriving "ought" propositions from it. R. Sartorius equally argues that the flaw in Hart's approach is to seek one simple concept of a valid law, whereas there is really a cluster concept, which means different things for different purposes. More so critics have further pointed out that there are doubts as to what constitutes the ultimate rules of recognition and that this problem may have to be resolved within the legal systems itself, possibly by recourse to such principles or guidelines”. The ascertainment of such rules can be properly be regarded as a question of law, argues sartorius. Here some other legal philosophers were not at home with Hart's concept of law.
R.M. DWORKIN'S CRITICISMS
In his book, "Is law a system of rules?" R.M. Dworkin attacked kelsem and Hart's view that the concept of law is explainable and exhaustible only be the concept of rule, or that a legal system can be fully explained in terms of system of rules. Law is not simple the application of rules, for there are other extra-legal standards which are applied in courts and which cannot be ignored as Hart has done in his concept of law.
To Dworkin, law consists of other standards as well as rules. It is impossible to maintain a distinction between what the law is and what, morally speaking, it ought to be. This is because “the non-rule standards which judges employ in order to determine what the law is in hard cases include principles embedded in the community's morality. It is community's interest that informs the judges on how to decide a case.
Dworkin gives the example of the case of Riggs vs. Palmer in 1889, when a New York court had to decide whether a murderer who had killed his grandfather in order to inherit his property should be allowed to actually inherit the property. The grandfather had made a will in which he named this grandson as his heir. Thus, according to law, in the positivist sense, the murderer should be allowed to inherit the property of his murdered grandfather. But there is bar here, which says that no man may profit from his own wrong deed, and this was resorted to in the court.
