The recognized methods of political science may be classified as the experimental, the so ciological, the comparative and the historical. To some extent states may also be studied biologically and psychologically and recently these latter methods have received much atten tion. The older and more generally accepted methods, however, are the comparative and his torical methods. The comparative method was first employed by Aristotle and later by Mon tesquieu, de Tocqueville, Laboulaye, Mill and Bryce. This, method aims through the corn panson of existing polities to assemble a definite body of knowledge from which the ideal types of constitutions may be discovered. The historical method consists in the study of constitutions in their development and political working with a view to determining how far they have adapted themselves to existing needs and have fulfilled their original purposes. seeks,* says Sir Frederick Pollock, ((an expla nation of what institutions are and are tending to be, more in the knowledge of what they have been and how they came to be what they are than in the analysis of them as they stand." The experimental method in political science is obviously less satisfactory because the phe nomena of government cannot be subjected to the process of artificial experimentation in the same way that physical phenomena may be analyzed and studied by the chemist, the physi cist or the biologist. The latter may with the aid of applicances, heat, chemicals and the like isolate the phenomena which he desires to study, subject them to artificial processes and exclude the operation of disturbing influences. But the political scientist cannot do this. He cannot select a state, create artificial conditions for its study, employ mechanical apparatus and draw precise conclusions from the results. Never theless, the experimental method in politics is not entirely impossible. Indeed the whole po litical life of the state is in a sense a succession of experiments. Every new law, every new institution, every new administrative policy is experimental in the sense that it is regarded as tentative and provisional until experience has demonstrated its fitness to be retained per manently. In this way what Bacon called ex perimenta fructifera are constantly being made on every community, consciously or uncon sciously. • Historically political science began with the ancient Greeks. Other primitive races lacked political consciousness. They had the conscious ness of family and of class, but not of the state in the aggregate. By the common voice of posterity Aristotle (q.v.) is recognized as the founder of political science and his commenta ries still occupy an important place in the literature of the subject. He it was who first gave to politics the character of an independent science. He mastered in the concrete a large number of constitutions, mostly Greek, and from the mass of facts thus gathered he laid down the body of general principles which constitute his system of politics. He was the first to classify governments as monarchies, aristoc racies and democracies and although many of his other theories have long since been rejected this classification is still accepted as the most scientific and convenient. The corresponding perversions he designated as tyrannies, oli garchies and democracies. He laid down the important maxim that man is by nature a polit ical animal and that, therefore, the state is necessary to a complete and all-sufficing life; he drew a distinction between ethics and politics ; taught that the state was not an affair of mere convention but the result of growth and evolu tion; and discussed with scientific method the various types and forms of government, the theory of sovereignty, the institution of slavery and private property. Three elements, he said, were essential to every government. They were: a deliberative organization, a system of magistrates and a judicial organization. He asserted that the best constitution is one framed and administered for the common good, but that the best for one people was not necessarily good for all ; that some are born to command and others to obey; he emphasized the principle of the responsibility of power and expressed the opinion that government by the middle classes was the most desirable. The chief merit of Aristotle's work was that he studied exhaus tively the materials at hand and reduced to a clean-cut systematic form the general principles which he was able to gather from his studies. In other words he created a science of politics. Among his countrymen Plato (q.v.) was the only other scholar who contributed anything worth mentioning to political science and his treatment of politics was largely incidental to his ethical philosophy, it scarcely ever rising to the dignity of a science. In the which was the greatest of his works, he formu lated the conception of a state in which abso lute justice prevails — an ideal commonwealth such as has never existed, in fact, nor probably ever will. Three classes, he affirmed, were necessary to every state. They were producers, warriors and magistrates, and every member must be assigned to the class for which he is best fitted. He did not recognize the right of private property, but insisted upon a uniform system of public education. In fact he believed that the only true way to the perfect state was through education. The function of the magis trates was to be limited—practically to the training of children, every detail of their early life being prescribed by the state. His idea of government was that of the aristocratic form; but he believed in an aristocracy of merit rather than of wealth. He proposed that philosphers should constitute the governing class, to ex dude poetry from the state, to place women on an equality with man so far as political and military obligations were concerned. Some of his teachings, however, were not purly utopian; such for example as the opinion that the strength of the state was virtue and education, and that the guaranty of civil liberty could only be bad in a well-balanced constitution. His classification of governments was the same as that of Aristotle except that he added two other types, namely, tyranny and oligarchy. In the 'Laws,' which is his last and most extensive treatise, he abandons somewhat his utopianism and seeks to present a practical code for the government of men. It proposed regulations for the minutest details of domestic life and recognized the institutions of marriage and pri vate property, which had no place in his earlier treatises. It was he, as Sir Frederick Pollock shows, who first worked out the theory that government is a special art and can be exercised only by competent persons. His idea of govern ment by philosophers, however, would now be ridiculed. Strictly speaking, he had no theory of the state, and his political ideas generally have had little permanent influence upon the history of The same may be said of the post Aristotelian Greek scholars, although it may be said that the Stoics contributed the idea of the law of nature and the idea of citizenship.
In the domain of political science the Romans were servile imitators of the Greeks and, there fore, contributed little of permanent influence. They were successful rulers and administrators, were skillful in the formation of rights and ac complished wonders in the domain of jurispru dence, but when Rome became a world state, carrying with it the destruction of all indepen dent political life, there was no place for theret ical politics. The Latin mind, in fact, was not given to speculation. Polybius and Cicero are almost the only names among the Roman theorizers, and their investigations were con fined entirely to the Roman state. Polybius produced a remarkable treatise on the constitu tion of Rome which had an important influence upon later Roman politics. His discussion of the forms of government is also worthy of note.
In Cicero's political writings, of which the 'Laws' and the 'Republic' were the most notable, we find developed the idea of a mixed government, containing royal, aristocratic and popular elements — a type which Cicero believed would prove to be most stable because of its triune basis. His classification of government was the same as that of Aristotle. Cicero's most important contribution to political science was the presentation of a clear and definite conception of natural law, which he defined as the supreme principle common to all nations.
During the Middle Ages few or no im portant contributions were made to political science. As James Bryce points out the Media- val period was essentially unpolitical. The de cisive spiritual force was religion. Political self-consciousness was lacking. One and only one great question dominated the political and intellectual life of the time and that was the long controversy between the temporal and spiritual powers. It involved the relation of Church and State and incidentally the nature of the civil power, the principle of the divine right of kings and the sovereignty of the people. A number of scholars, mostly theologians, arose to defend the claims of the Church to su premacy over the civil power. Of these, John of Salisbury and Saint Thomas Aquinas were probably the most notable. In the (Polycrati cus' the former discusses monarchy as a form of government and justifies the crime of tyran nicide; in the (Summa Theologia,) one of the greatest treatises of the Middle Ages, the latter discusses various kinds of law, natural justice, the nature and forms of political authority and the functions of government. On the other hand, Dante, Occam, Marsiglio of Padua and other jurisconsults defended the claims of the civil power. To mention the most important of the numerous treatises that followed, Dante's
Monarchia) discussed the monarchial form of government as the best of all forms and as serted that a universal monarchy on the old imperial lines was necessary for the highest de velopment of mankind. A universal monarch, he said, having no rival to fear and no further ambition to satisfy, could have no motive for ruling unjustly. Occam's and Marsiglio's dis cussion of sovereignty and representations are of interest only to the student of political theory. Modern political science really begins with Machiavelli, an Italian who wrote during the latter part of the 15th century. He was devoted to the study of political science and like Aris totle regarded the state as the highest good. His chief works were the (Discourse on Livius' and the (Prince,' the latter a treatise which was designed to furnish advice to princes as to how they might best obtain their ends. The treatise is chiefly notable for its details of statecraft rather than for any theory of the state. It makes a complete separation of ethics and poli tics, in fact takes no account of morality. Into politics he introduces cruelty and bad faith, and teaches that a prince is justified in resorting to deceit, treachery, treason, cruelty and even mur der in order to accomplish his ends. For this purpose such conduct seemed to him to be per fectly innocent and he recommended it without scruple. In the following century an important contribution to the literature of political science was Languet's (Vindicim contra Tyrannos,' the first treatise which defined the relationship ex isting between rulers and subjects as one of contract. This is not to be confused with the principle of contract as a theory of the origin of the state. The work was also notable for its strong plea for resistance to rulers who violate the contract existing between them and the peo ple. A monumental contribution to political science was Jean Bodin's Republica,' pub lished in 1577. It is a polemical treatise con ceived on the plan of Aristotle's (Politics) and is notable for containing the first definite enun ciation of the modern political doctrine con cerning the nature and location of sovereignty. He shows that in every independent state there must be some authority, whether single or col lective, whereby the laws are enacted. This au thority is the sovereign and being the source of law must be supreme over the law. °I-le is sovereirp,x' said Bodin, ((who sees no one greater than himself except God." He defines sov ereignty as a ((power supreme over citizens and subjects, itself not bound by the laws,,' and asserted that it was a unit and hence indivisible. This view of sovereignty was in the following century adopted by Hobbes and ultimately came to be the generally accepted view of the pub licists. He is entitled, says Sir Frederick Pol lock, to share with Hobbes the renown of hav ing founded the modern theory of the state. In the 17th century the two most distinguished names in the annals of political science are those of Thomas Hobbes and John Locke, both Englishmen, one a defender of the absolutism of the Stuarts, the other a defender of the Revolution and a champion of the sovereignty of the people. Hobbes most famous treatise was the