Jurisprudence is that science which inquires into the general principles which ought to be the foundation of the laws of all nations. Grotius seems to have been the first who attempted to give the world anything like a regular system of natural jurisprudence, and his treatise On the Laws of War and Peace, with all its imperfections, is perhaps at this day the most complete work on this subject1. It is a sort of casuistical book for sovereigns and states, determining in what cases war may justly be made and how far it may be carried on. As states have no common sovereign and are with respect to one another in a state of nature, war is their only method of redressing injuries. He determines war to be lawful in every case where the state receives an injury which would be redressed by an equitable civil magistrate2. This naturally led him to inquire into the constitution of states and the principles of civil laws; into the rights of sovereigns and subjects; into the nature of crimes, contracts, property, and whatever else was the object of law, so that the two first books of  his treatise, which are upon this subject, are a complete system of jurisprudence.
The next writer of note after Grotius was Mr. Hobbes. He had conceived an utter abhorrence of the ecclesiastics, and the bigotry of his times gave him occasion to think that the subjection of the consciences of men to ecclesiastic authority was the cause of the dissensions and civil wars that happened in England during the times of Charles I and of Cromwell. In opposition to them he endeavoured to establish a system of morals by which the consciences of men might be subjected to the civil power, and which represented the will of the magistrate as the only proper rule of conduct. Before the establishment of civil society, mankind, according to him, were in a state of war; and in order to avoid the ills of a natural state, men entered into contract to obey one common sovereign who should determine all disputes. Obedience to his will, according to him, constituted civil government, without which there could be no virtue, and consequently it too was the foundation and essence of virtue.
The divines thought themselves obliged to oppose this pernicious doctrine concerning virtue, and attacked it by endeavouring to show that a state of nature was not a state of war, but that society might subsist, though not in so harmonious a manner, without civil institutions. They endeavoured to show that man in this state has certain rights belonging to him, such as a right to his body, to the fruits of his labour, and the fulfilling of contracts. With this design Puffendorf wrote his large treatise. The sole intention of the first part of it is to confute Hobbes, though it in reality serves no purpose to treat of the laws which would take place in a state of nature, or by what means succession to property was carried on, as there is no such state existing.
The next who wrote on this subject was the Baron de Cocceii, a Prussian. There are five volumes in folio of his  works published, many of which are very ingenious and distinct, especially those which treat of laws. In the last volume he gives an account of some German systems1.
Besides these there are no systems of note upon this subject.
[§ 2. Of the Division of the Subject.]
Jurisprudence is the theory of the general principles of law and government.
The four great objects of law are justice, police, revenue, and arms.
The object of justice is the security from injury, and it is the foundation of civil government.
The objects of police are the cheapness of commodities, public security and cleanliness, if the two last were not too minute for a lecture of this kind. Under this head we will consider the opulence of a state.
It is likewise necessary that the magistrate who bestows his time and labour in the business of the state should be compensated for it. For this purpose, and for defraying the expenses of government, some fund must be raised. Hence the origin of revenue. The subject of consideration under this head will be the proper means of levying revenue,  which must come from the people by taxes, duties, &c. In general, whatever revenue can be raised most insensibly from the people ought to be preferred; and in the sequel it is proposed to be shown, how far the laws of Britain and of other European nations are calculated for this purpose.
As the best police cannot give security unless the government can defend themselves from foreign injuries and attacks, the fourth thing appointed by law is for this purpose; and under this head will be shown the different species of arms with their advantages and disadvantages, the constitution of standing armies, militias, &c.
After these will be considered the laws of nations, under which are comprehended the demands which one independent society may have upon another, the privileges of aliens, and proper grounds for making war.