Italy in the Middle Ages presented a curious phenomenon: while in practice the authority of the state was being dissolved into a multiplicity of competing sovereignties, the theory of state unity and authority was kept alive in the minds of thinkers by the memories of the Roman Imperial tradition. It was this memory that supported for centuries the fiction of the universal Roman Empire when in reality it existed no longer. Dante's _De Monarchia_ deduced the theory of this empire conceived as the unity of a strong state. "Quod potest fieri per unum melius est per unum fieri quam plura," he says in the XIV chapter of the first book, and further on, considering the citizen as an instrument for the attainment of the ends of the state, he concludes that the individual must sacrifice himself for his country. "Si pars debet se exponere pro salute totius, cum homo siti pars quaedam civitatis ... homo pro patria debet exponere se ipsum." (lib. II. 8). The Roman tradition, which was one of practice but not of theories--for Rome constructed the most solid state known to history with extraordinary statesmanship but with hardly any political writings--influenced considerably the founder of modern political science, Nicolo Machiavelli, who was himself in truth not a creator of doctrines but a keen observer of human nature who derived from the study of history practical maxims of political import. He freed the science of politics from the formalism of the scholastics and brought it close to concrete reality. His writings, an inexhaustible mine of practical remarks and precious observations, reveal dominant in him the state idea, no longer abstract but in the full historical concreteness of the national unity of Italy. Machiavelli therefore is not only the greatest of modern political writers, he is also the greatest of our countrymen in full possession of a national Italian consciousness. To liberate Italy, which was in his day "enslaved, torn and pillaged," and to make her more powerful, he would use any means, for to his mind the holiness of the end justified them completely. In this he was sharply rebuked by foreigners who were not as hostile to his means as they were fearful of the end which he propounded. He advocated therefore the constitution of a strong Italian state, supported by the sacrifices and by the blood of the citizens, not defended by mercenary troops; well-ordered internally, aggressive and bent on expansion. "Weak republics," he said, "have no determination and can never reach a decision." (Disc. I. c. 38). "Weak states were ever dubious in choosing their course, and slow deliberations are always harmful." (Disc. I. c. 10). And again: "Whoso undertakes to govern a multitude either in a régime of liberty or in a monarchy, without previously making sure of those who are hostile to the new order of things builds a short-lived state." (Disc. I. c. 16). And further on "the dictatorial authority helped and did not harm the