Since I was A2A the original question (now changed) I feel obliged to update my answer to include “law” in addition to “legal theory.”
In the broadest sense, “jurisprudence” is the study of the nature of law, methods of legal reasoning, legal systems, and legal institutions. Its study covers such concepts as how we know what law is, what are the sources of law and any obligation to obey it, and what difference there is between law and justice. Often included is analysis of how competing concepts of liberty, equality, neutrality, and choice of law affect judicial decisions. The focus is on the practical application of legal concepts.
“Legal theory” is more strictly academic, since it is the examination of different intellectual traditions that have shaped the law: natural law and natural rights, legal positivism, legal realism, Marxism, feminist legal theory, and postmodern legal theory.
“Law”is a system of rules regulating the activities of a particular group of humans and penalties for breaking those rules.
Law are the rules that members of society must follow.
Jurisprudence deals with the why questions, rather than the what questions. For example, the law might state that the death penalty will be imposed on anyone who intentionally kill’s the nation’s leader. The why question involves asking whether intent should be a requirement or whether the death penalty is ever appropriate.
What is the difference between jurisprudence and criminal law?
In jurisprudence you deal with theories, ideology, propositions, proofs, and philosophy. You are familiar with works by Immanual Kant, Jeremy Bentham, H.L.A. Hart, and Ronald Dworkin, to name a few of the philosophers in the subject areas.
Criminal law is part of the substantive law within many nations. the individual within the discipline/profession is concerned with the practical applications of the law. You will read works by Learned Hand, William Blackstone, Antonin Scalia, and other judges who write the legal opinions which are used to apply the law.
A practitioner from the criminal law field will have a Juris Doctor (J.D.) degree, most likely. There are some who hold the Bachelor of Law (LL.B.) degree, but in the United States that number is being diminished.
In jurisprudence, you may see a number of the theorist who hold a J.D. degree, but often they may hold a different doctorate degree. Once must remember that the J.D. degree is non-terminal doctorate, meaning that there is no research component and that there are other degrees above it. It is a practitioner or professional doctorate.
Above the J.D. degree is the Doctor of Philosophy (Ph.D.), which can be granted through many disciplines, and the Doctor of Science of Law (J.S.D.) degree. Both of these doctorates are considered terminal degrees, meaning there are none higher, and they both often involve lots of work with theory and philosophies of the discipline. Research, with the need to “contribute new work to the field” is an important part of the degree, and it is usually presented through the dissertation.
Jurisprudence is either the theory and philosophy of law and judgment, or a particular entire body of law and legal system (as in the jurisprudence of a certain society or country). In other words it is the entire field of law and everything ever written, spoken or thought about it, whether civil or criminal.
Criminal law is legal practice or written statutes and judicial opinions concerning crimes only.
What is the difference between principles, maxims, doctrines, jurisprudence and conventions of law?
- A “principle” is a fundamental element of applying a law. For example, the need for a contract to have consideration is a principle of common law – it’s unknown in the civil code countries like France.
- A “maxim” is a pithy easy to remember phrase to remind you of a legal principle. A good one is “those seeking equity must do equity” – if you are seeking an equitable remedy at law (like specific performance of a contract), you must come with “clean hands” – not having done something that should deny you a remedy based on fundamental fairness.
- A “doctrine” is a set of principles to apply in determining whether the conditions of a legal principle have been met. For example, if we’re talking about consideration, there’s a doctrine that it’s not enough to merely mention it in the contract – the consideration has to be validly tendered and accepted.
- Jurisprudence is the study of the philosophy of law, essentially why the law is the way it is. It can cover the law as a whole (such as the concept of “natural law”) or a particular subsection of the law, such as why criminal laws are enforced the way they are.
- A convention is a general statement of principles without legal force but which generally reflect common agreement on the subject, like the Geneva Conventions on the treatment of prisoners of war or the International Convention of Human Rights.
What is the difference between Jurisprudence and philosophy of Law?
If you were going to draw a distinction, Jurisprudence is the body of principles and practices that underlie a legal system, particularly as it applies to the work of applying and adjudicating laws (e.g. lawsuits, legal review, interpretive rules). It is directed to the practice of law.
Philosophy of law is just that, philosophy. It borders up against logic, metaphysics, ethics, what is right and wrong, what it means to agree with something, what justice and fairness are. Some would consider that a subset of jurisprudence.
Whereas jurisprudence might ask “what are the rules for deciding if a person has caused harm to another”, legal philosophy might ask “what is causation” or “what does it mean to be a person”?