Jurisprudence is the science or philosophy of law. Jurisprudence deliberates law from tracing its origin, functions, nature of law and the relationship between law and other subjects. History provides that, law was created by man within the society so as to regulate their relationship in different aspects such as in contractual terms.
The oxford English Dictionary perpetuate that, jurisprudence is demarcated as the knowledge or skills in law, the science which treats human laws in general, the philosophy of law, the system or body of law. By that meaning, jurisprudence can be defined as systematic and scientific investigation into law. Jurisprudence in its limited sense means elucidation of the general principles upon which actual rules of law are based. It is concerned with rules of external conduct which persons are constrained to obey.
Jurisprudence is that science which imparts to us the knowledge about law. Jurisprudence consists of scientific and philosophical investigations of the social phenomenon of law and of justice generally. It embraces studies, theories and speculations about law and justice undertaken with the knowledge and theoretical tools of different disciplines. Thus, the knowledge of jurisprudence provides answers to questions such as what is law? How do the judges decide cases? How does the law shape the society? What is natural justice and what are its minimum demands?
The word Jurisprudence originates from Latin words ‘Juris and prudentia’ whereby the word juris means law and right respectively whereas prudentia means the knowledge or skills of law, knowledge of skills of law.
From the above perspective, it makes sagacity to state that jurisprudence is the eye of law.
The statement is supported by the fact that; eyes are one of the most important part of human body. Almost all human activities and the movements of body are possible only through them. Unless man can see anything properly, he cannot do any work. That is to say when scalling jurisprudence as the eye of law, the reason is that the function of law in the same manner as eyes do in human body.
Example, the interpretation of law is a difficult task, it cannot be done without the gigantic knowledge of jurisprudence. Also jurisprudence is the eye of law. because it is the grammar of law, it throws light on the basic ideas and fundamental principles of law. Jurisprudence teaches the lawyer and legislator the correct use of legal terms by providing a precise and unambiguous terminology, which is so essential for their task of pleading and legislation. It also brings about homogeneity and accuracy in legal phraseology. As seen above, from the concept of jurisprudence the following are the different scholars who by their efforts discussed jurisprudence in details.
Jurisprudence is the eye of law as substantiated by the following significances of jurisprudence-
- It sharpens the logical, legal reasoning and professional skills of a lawyer; in a practical work of a lawyer, he is faced by new problems from interpretation and application of different laws in his activities. Thus, it is necessary to tackle those problems so as to expedite his activities. With the cosmic knowledge of jurisprudence, a lawyer can handle his work efficiently with alternative legal channel of thoughts in his mind. A practicing lawyer is constrained, if not by a definition of law, at least by the way law is understood by judges and other officials who enforce the law. A good lawyer is one who knows when to argue strictly from statutes and precedents, when to re-interpret laws or distinguish precedents and when to appeal to policy, justice or the good sense of the judge. That is to say, jurisprudence is the eye of law as it shone light to a lawyer in his undertakings therein.
- Jurisprudence trains critical thinking; this accompanied by being competent to use accurate legal terminologies and expression. That is to say, the knowledge of jurisprudence teaches people to look not only forward, at least sideways and around them and realize that answers to a new legal problem must be found by a consideration of present social needs and not in the wisdom of the past.
- This is well exemplified In the case of Speluncean Explorers, the defendants having been indicted for the crime of murder, were convicted and sentenced to be hanged by the Court of General Instances of the County of Stowfield. They decided to appeal against the decision. The four defendants were the among five casualties who were trapped inside the cave where the landslide occurred. In the course of trying to rescue them, 10 men engaged were killed. On the 20th day, the explorers communicated with the workmen outside the cave asking to eat the flesh of one of themselves so that they can survive. No one permitted so. they casted a vote by dice and one of them was killed and eaten by others. After being rescued they were charged by the offence in question. Critically thinking, Justice Forster argued in favor of the defendants ascertaining positive law and natural law. He argued that, since the explorers were isolated from the society, positive law no longer applies to them.
- Hence eating one of them for purpose of surviving was according to natural law and they were not subjected to positive laws. He further provided examples that, 10 men died during the rescue, so 10 men were sacrificed to save 5 men then why it is not possible to sacrifice 1 so as to save 4? doing what is necessary for survival should not end up in punishment. Justice Foster went on and say that, a man may break the letter of law without breaking the law itself. The statement simply denotes that, killing on selfdefense is excused but it is not suggested in statues. Thus, with this line of rational thinking, jurisprudence is the eye of law.
- Jurisprudence also has an educational value; this is because jurisprudence has its own intrinsic interest and value because this is a subject of serious scholarship and research; researchers in Jurisprudence contribute to the development of society by having repercussions in the whole legal, political and social school of thoughts. One of the tasks of this subject is to construct and elucidate concepts serving to render the complexities of law more manageable and more rational. It is the belief of this subject that the theory can help to improve practice.
Jurisprudence helps the judges and lawyers in ascertaining the true meaning of the laws passed by the legislators by providing the rules of interpretation;knowledge of jurisprudence facilitates interpretation of law enacted by the legislator and hence it facilitates the dispensation of justice. Without the knowledge of jurisprudence, it is hard to interpret different laws.
The study of jurisprudence is also an opportunity for lawyers to bring theory and life into focus. Jurisprudence concerns human thought in relation to social existence. With the knowledge of jurisprudence, a lawyer can be able to apply law and to take note of the needs of society and of the advances in the related and relevant disciplines such as sociology, economics, philosophy etc. It is not the form of law but the social function of law which has relevance in modern jurisprudence.
Jurisprudence is the eye of law, it is essential for a lawyer, in his practical work, to have knowledge of jurisprudence. Jurisprudence serves to train the mind into legal ways of thought. It affords a key to the solution of many provisions of civil law, which would otherwise appear to be singular and unaccountable. Thus, without such knowledge, no lawyer, however eminent, can really measure the meaning of the assumptions upon which his subject rests.
 Salmond, J (1920). Jurisprudence, 6th ed. Sweet And Maxwell, Limited, 3, Chanoeey Lane,
W.C. 2. Law publishers, London.
 Harvard Law Review vol. 62, No 4 February 1949