John Locke would have agreed with all of these statements except the notion that mankind, when living in a state of nature, is barbaric and brutish. This is an idea that is credited to Thomas Hobbes. Hobbes and Locke are often contrasted against one another, Locke the prototypical liberal, Hobbes the prototypical conservative. And indeed there is much truth in this comparison. Locke believed that mankind existed peacefully in a state of nature, whereas Hobbes believed that mankind was wicked and brutish in a state of nature and that the role of government was to protect mankind from the worst excesses of its own nature. Hobbes believed an authoritarian government was vital to keep society from spiraling into chaos and bloodshed.

The Renaissance was a pan-European phenomenon triggered by a rediscovery of classical knowledge during the Crusades. The artistic accomplishments of the Renaissance in Italy are an important part of that phenomenon, but they do not accurately describe it on their own. The Renaissance is also not to be confused with the Middle Ages, the Reformation, or the Scientific Revolution.

The term “Westphalian Sovereignty” refers to the terms of the Peace of Westphalia which brought to an end the hostilities of the Thirty Years’ War. The Thirty Years’ War was one of the bloodiest and most brutal wars in European history. It was a complicated war with many phases and shifting alliances. It was primarily fought as a rivalry between Catholicism and Protestantism, and as a conflict between secular and religious authority. The term “Westphalian Sovereignty” is used to describe the principle of international law which states that each nation has exclusive sovereignty over its own territory and its own domestic affairs. This is a key concept in European international relations that, due to the spread of European nation-state construction, prevails around the world to this day.

The French philosopher and political thinker Baron de Montesquieu is most famous for his development of the idea of “separation of powers” in government. According to Montesquieu and his seminal text Spirit of the Laws, the best way to ensure against tyranny government is to maintain separate branches of government, each with their own particular area of authority and each able to check the power of the others. This theory is enshrined in the constitutions of many modern democracies, including the United States.

Thomas Hobbes is often contrasted with John Locke. Locke had a very positive outlook on human nature and an inclusive concept of politics and government, whereas Hobbes had a very negative outlook on human nature and an authoritarian concept of politics and government. Thomas Hobbes’ most famous work is The Leviathan (1651), in which he argues for the necessity of authoritarianism in governance. It is worth noting that Hobbes also laid much of the groundwork for later explorations of the rights of man, limits of the law, and consent of the governed. But, it is for his pessimistic and negative statement that Hobbes is most frequently remembered - “[Mankind, in a state of nature, lives in a constant state of war] . . . and worst of all, continual fear, and danger of violent death: and the life of man, solitary, poor, nasty, brutish, and short.”

Deism is associated with the Scientific Revolution because it attempted to explain how God could co-exist with the newly-discovered laws of science. The idea of a watchmaker fits most closely with those requirements, because it embraces the idea that world was created by a higher power but rejects the idea of divine intervention after creation.

The humanist philosophy of studying the classics, celebrating human achievement, and focusing on individuality touched nearly every aspect of Renaissance art and literature. Shakespeare expressed interest in the classics by frequently using them as settings and subjects for his plays, while both Michelangelo and Hans Holbein created paintings that shared the classical love of the human form. Erasmus and Thomas More infused their humanist writings with Christianity, often using satire to raise questions about morality and human nature. However, Henry VIII's Act of Supremacy had little to do with humanism, as it was largely a political move.

Jean-Jacques Rousseau was famous for his theory that society must obey the general will of the people, an idea which would later become highly influential on the French Revolution; however, many other Enlightenment philosophers presented ideas about how society should be run: Montesquieu and Voltaire argued for separation of powers and religious toleration, respectively, while Thomas Hobbes believed that men are innately bad and must be ruled by a powerful leader called a Leviathan. John Locke took a different stance, arguing that the mind was a blank slate, or tabula rasa, at birth, and men are innately good.

Hobbes was primarily interested in political philosophy and he wrote The Leviathan, so he is the correct choice. Voltaire was a French political philosopher concerned with politics, however he did not write the work in question, so he would not be a good choice. Rene Descartes and Jean-Paul Sartre are also French thinkers, but they did not write The Leviathan either, so neither of them would be good choices.

René Descartes advocated very strongly for systematic doubt and dualism in his seminal philosophical work Meditations on First Philosophy, so that would be the best choice. Aristotle and Aquinas were great thinkers, but they lived far before Dualism was a commonly discussed intellectual topic. Voltaire was also a French philosopher, but he was generally concerned with ethical and political philosophy, not epistemology. Lastly Karl Popper was a philosopher of science in the 20th century, so he lived far after Dualism was a popular topic of discourse.