See J. Hall, ed., Readings in Jurisprudence (1938); W. S. Carpenter, Foundations of Modern Jurisprudence (1958); D. Lloyd, Introduction to Jurisprudence (3d ed. 1972).
Jurisprudence is the theory and philosophy of law. Scholars of jurisprudence, or legal philosophers, hope to obtain a deeper understanding of the nature of law, of legal reasoning, legal systems and of legal institutions. As jurisprudence has developed, there are three main aspects with which scholarly writing engages:
Modern jurisprudence and philosophy of law is dominated today primarily by Western academics. The ideas of the Western legal tradition have become so pervasive throughout the world that it is tempting to see them as universal. Historically, however, many philosophers from other traditions have discussed the same questions, from Islamic scholars to the ancient Greeks.
Jurisprudence already had this meaning in Ancient Rome, even if at its origins the discipline was a monopoly of the College of Pontiffs (Pontifex), which retained an exclusive power of judgment on facts, being the only experts (periti) in the jus of traditional law (mos maiorum, a body of oral laws and customs verbally transmitted "by father to son"). Pontiffs indirectly created a body of laws by their pronunciations (sententiae) on single concrete (judicial) cases.
Their sentences were supposed to be simple interpretations of the traditional customs, but effectively it was an activity that, apart from formally reconsidering for each case what precisely was traditionally in the legal habits, soon turned also to a more equitative interpretation, coherently adapting the law to the newer social instances. The law was then implemented with new evolutive Institutiones (legal concepts), while remaining in the traditional scheme. Pontiffs were replaced in 3rd century BC by a laical body of prudentes. Admission to this body was conditional upon proof of competence or experience.
Under the Roman Republic, schools of law were created, and the activity constantly became more academic. In the age from the early Roman Empire to the 3rd century, a relevant literature was produced by some notable groups including the Proculians and Sabinians. The degree of scientific depth of the studies was unprecedented in ancient times and reached still unrivaled peaks of skill. It is about this activity that it has been said that Romans had developed an art out of the law.
After the 3rd century, Juris prudentia became a more bureaucratic activity, with few notable authors. It was during the Byzantine Empire (5th century) that legal studies were once again undertaken in depth, and it is from this cultural movement that Justinian's Corpus Juris Civilis was born.
Aristotle is often said to be the father of natural law. Like his philosophical forefathers, Socrates and Plato, Aristotle posited the existence of natural justice or natural right (dikaion physikon, δικαιον φυσικον, Latin ius naturale). His association with natural law is due largely to the interpretation given to him by Thomas Aquinas. This was based on Aquinas' conflation of natural law and natural right, the latter of which Aristotle posits in Book V of the Nicomachean Ethics (= Book IV of the Eudemian Ethics). Aquinas' influence was such as to affect a number of early translations of these passages, though more recent translations render them more literally.
Aristotle notes that natural justice is a species of political justice, viz. the scheme of distributive and corrective justice that would be established under the best political community; were this to take the form of law, this could be called a natural law, though Aristotle does not discuss this and suggests in the Politics that the best regime may not rule by law at all.
The best evidence of Aristotle's having thought there was a natural law comes from the Rhetoric, where Aristotle notes that, aside from the "particular" laws that each people has set up for itself, there is a "common" law that is according to nature. The context of this remark, however, suggests only that Aristotle advised that it could be rhetorically advantageous to appeal to such a law, especially when the "particular" law of ones' own city was averse to the case being made, not that there actually was such a law; Aristotle, moreover, considered two of the three candidates for a universally valid, natural law provided in this passage to be wrong. Aristotle's theoretical paternity of the natural law tradition is consequently disputed.
Sharia (شَرِيعَةٌ) refers to the body of Islamic law. The term means "way" or "path"; it is the legal framework within which public and some private aspects of life are regulated for those living in a legal system based on Islamic principles of jurisprudence. Fiqh is the term for Islamic jurisprudence, made up of the rulings of Islamic jurists. A component of Islamic studies, Fiqh expounds the methodology by which Islamic law is derived from primary and secondary sources.
Mainstream Islam distinguish fiqh, which means understanding details and inferences drawn by scholars, from sharia that refers to principles that lie behind the fiqh. Scholars hope that fiqh and sharia are in harmony in any given case, but they cannot be sure.
Saint Thomas Aquinas [Thomas of Aquin, or Aquino] (c. 1225 – 7 March 1274) was a philosopher and theologian in the scholastic tradition, known as "Doctor Angelicus, Doctor Universalis". He is the foremost classical proponent of natural theology, and the father of the Thomistic school of philosophy, for a long time the primary philosophical approach of the Roman Catholic Church. The work for which he is best-known is the Summa Theologica. One of the thirty-three Doctors of the Church, he is considered by many Catholics to be the Church's greatest theologian. Consequently, many institutions of learning have been named after him.
Aquinas distinguished four kinds of law. These are the eternal, natural, human, and divine law. Eternal law is the decree of God which governs all creation. Natural law is the human "participation" in the eternal law and is discovered by reason. Natural law, of course, is based on "first principles":
In his treatise Leviathan, (1651), Hobbes expresses a view of natural law as a precept, or general rule, found out by reason, by which a man is forbidden to do that which is destructive of his life, or takes away the means of preserving the same; and to omit that by which he thinks it may best be preserved. Hobbes was a social contractarian and believed that the law gained peoples' tacit consent. He believed that society was formed from a state of nature to protect people from the state of war between mankind that exists otherwise. Life is, without an ordered society, "solitary, poore, nasty, brutish and short". It is commonly commented that Hobbes' views about the core of human nature were influenced by his times. The English Civil War and the Cromwellian dictatorship had taken place, and he felt absolute authority vested in a monarch, whose subjects obeyed the law, was the basis of a civilized society.
Analytic, or 'clarificatory' jurisprudence is using a neutral point of view and descriptive language when referring to the aspects of legal systems. This was a philosophical development that rejected natural law's fusing of what law is and what it ought to be. David Hume famously argued in A Treatise of Human Nature
that people invariably slip between describing that the world is a certain way to saying therefore we ought to conclude on a particular course of action. But as a matter of pure logic, one cannot conclude that we ought to do something merely because something is the case. So analysing and clarifying the way the world is must be treated as a strictly separate question to normative and evaluative ought questions.
The most important questions of analytic jurisprudence are: "What are laws?"; "What is the law?"; "What is the relationship between law and power/sociology?"; and, "What is the relationship between law and morality?" Legal positivism is the dominant theory, although there are a growing number of critics, who offer their own interpretations.
One of the earliest legal positivists was Jeremy Bentham. Bentham was an early and staunch supporter of the utilitarian concept (along with Hume), an avid prison reformer, advocate for democracy, and strongly atheist. Bentham's views about law and jurisprudence were popularized by his student, John Austin. Austin was the first chair of law at the new University of London from 1829. Austin's utilitarian answer to "what is law?" was that law is "commands, backed by threat of sanctions, from a sovereign, to whom people have a habit of obedience". Contemporary legal positivists have long abandoned this view, and have criticised its oversimplification, H.L.A. Hart particularly.
Hans Kelsen is considered one of the preeminent jurists of the 20th century. He is most influential in Europe, where his notion of a Grundnorm or a "presupposed" ultimate and basic legal norm, still retains some influence. It is a hypothetical norm on which all subsequent levels of a legal system such as constitutional law and "simple" law are based. Kelsen's pure theory of law described the law as being a set of social facts, which are normatively binding too. Law's normativity, meaning that we must obey it, derives from a basic rule which sits outside the law we can alter. It is a rule proscribing the validity of all others.
Kelsen was a Professor at several universities in Europe, notably the University of Vienna and the University of Cologne. In 1940, he moved to the United States, giving the Oliver Wendell Holmes Lectures at Harvard Law School in 1942 and becoming a full professor at the department of political science at the University of California, Berkeley in 1945. During those years, he increasingly dealt with issues of international law and international institutions such as the United Nations.
Rules, said Hart, are divided into primary rules (rules of conduct) and secondary rules (rules addressed to officials to administer primary rules). Secondary rules are divided into rules of adjudication (to resolve legal disputes), rules of change (allowing laws to be varied) and the rule of recognition (allowing laws to be identified as valid). The "rule of recognition", a customary practice of the officials (especially judges) that identifies certain acts and decisions as sources of law. A pivotal book on Hart was written by Neil MacCormick
in 1981 (second edition due in 2007), which further refined and offered some important criticisms that led MacCormick to develop his own theory (the best example of which is his recently published Institutions of Law, 2007). Other important critiques have included that of Ronald Dworkin, John Finnis, and Joseph Raz.
In recent years, debates about the nature of law have become increasingly fine-grained. One important debate is within legal positivism. One school is sometimes called exclusive legal positivism, and it is associated with the view that the legal validity of a norm can never depend on its moral correctness. A second school is labeled inclusive legal positivism, and it is associated with the view that moral considerations may determine the legal validity of a norm, but that it is not necessary that this is the case.
Ronald Dworkin is a leading philosopher. In his book 'Law's Empire' Dworkin attacked Hart and the positivists for their refusal to treat law as a moral issue. Dworkin argues that law is an 'interpretive' concept, that requires judges to find the best fitting and most just solution to a legal dispute, given their constitutional traditions. According to him, law is not entirely based on social facts, but includes the morally best justification for the institutional facts and practices that we intuitively regard as legal. It follows on Dworkin's view that one cannot know whether a society has a legal system in force, or what any of its laws are, until one knows some moral truths about the justifications for the practices in that society. It is consistent with Dworkin's view--in contrast with the views of legal positivists or legal realists--that *no one* in a society may know what its laws are (because no one may know the best justification for its practices.)
Interpretation, according to Dworkin's law as integrity theory, has two dimensions. To count as an interpretation, the reading of a text must meet the criterion of fit. But of those interpretations that fit, Dworkin maintains that the correct interpretation is the one that puts the political practices of the community in their best light, or makes of them the best that they can be. But many writers have doubted whether there is a single best justification for the complex practices of any given community, and others have doubted whether, even if there are, they should be counted as part of the law of that community.
Legal realism was a view popular with some Scandinavian and American writers. Skeptical in tone, it held that the law should be understood and determined by the actual practices of courts, law offices, and police stations, rather than as the rules and doctrines set forth in statutes or learned treatises. It had some affinities with the sociology of law. The essential tenet of legal realism is that all law is made by human beings and, thus, is subject to human foibles, frailties and imperfections.
It has become quite common today to identify Justice Oliver Wendell Holmes, Jr., as the main precursor of American Legal Realism (other influences include Roscoe Pound, Karl Llewellyn and Justice Benjamin Cardozo). Karl Llewellyn, another founder of the U.S. legal realism movement, similarly believed that the law is little more than putty in the hands of a judge who is able to shape the outcome of a case based on personal biases. The chief inspiration for Scandinavian legal realism many consider to be the works of Axel Hägerström. Despite its decline in facial popularity, realists continue to influence a wide spectrum of jurisprudential schools today, including critical legal studies (scholars such as Duncan Kennedy and Roberto Unger), feminist legal theory, critical race theory, and law and economics.
Aretaic moral theories such as contemporary virtue ethics emphasize the role of character in morality. Virtue jurisprudence is the view that the laws should promote the development of virtuous characters by citizens. Historically, this approach is associated mainly with Aristotle or Thomas Aquinas later. Contemporary virtue jurisprudence is inspired by philosophical work on virtue ethics.
Deontology is "the theory of duty or moral obligation. The philosopher Immanuel Kant formulated one influential deontological theory of law. He believed that morality is what if I do, would be good for everyone to do. A contemporary deontological approach can be found in the work of the legal philosopher Ronald Dworkin.
Utilitarianism is the view that the laws should be crafted so as to produce the best consequences. Historically, utilitarian thinking about law is associated with the great philosopher, Jeremy Bentham. John Stuart Mill was a pupil of Bentham's and was the torch bearer for utilitarian philosophy through the late nineteenth century. In contemporary legal theory, the utilitarian approach is frequently championed by scholars who work in the law and economics tradition.
There are many other normative approaches to the philosophy of law, including critical legal studies and libertarian theories of law.

Navigate to page for Encyclopedia of the Science of Law (Mellen, 2002).
