*In the ancient world, and thus in the Mediæval and Renaissance eras that followed, natural philosophy (as science was known) truly was philosophical, in which known premises were considered and treated as rules until conclusions could be reached.  Future expectations were based on past experience, but not necessarily on actual tests.  A few exceptions existed during the Middle Ages, but the age of experimentation would not begin really until the 1600s.

*One of the first natural philosophers to truly experiment—test his theories rather than just reason out what ought to happen—was Sir Francis Bacon of England.  Like earlier natural philosophers, he collected all the information he could about a subject and tried to work out general rules from them.  However, he would them experiment to test the rules that he had deduced.  It is even said that he died as a result of his experiments:  while travelling in the winter with a friend (the King's physician), they discussed the possibility that cold could preserve meat.  They stopped at a farm, bought a chicken, had it killed, and stuffed it with snow.  While staying at the farm to see if the chicken would rot, Bacon caught pneumonia and died (after eating the chicken).  Bacon made no great discoveries during his life, but he did help to establish the modern scientific method.

*Another early experimenter was Galileo Galilei.  He, like everyone, accepted Aristotle's statement that heavy things naturally fall faster than light things.  One day, though, he decided to find out, by dropping items of varying sizes and weights off the Leaning Tower of Pisa, and found that they all fell at the same speed—or so the legend goes.  Even if that story is a mere myth, it is true that he experimented with light and mechanical physics, studied astronomy and applied physics to the motions of the planets and the tides.  Although not all of his theories were correct (and some were banned by the Pope), they (and the astronomical work of Tycho Brahe of Denmark/Sweden (who had the bridge of his nose cut off during a drunken night-time duel and wore a silver, gold, or copper prosthetic (with skin-coloured makeup over it)) and his apprentice, Johannes Kepler of Germany) formed the framework upon which the sciences of Physics and Astronomy would be built.  They also established that the Earth (and therefore Man) was not the centre of the Universe.

*The true father of Physics was Sir Isaac Newton, who had first developed calculus to be able to mathematically explain his theories (although credit also goes to Gottfied Leibniz of Germany who developed and published the fundamental theorem of calculus independently and simultaneously).  In 1687 Newton published Philosophiæ Naturalis Principia Mathematica, which put form his laws of gravity and motion and formed the basis of the study of physics.

*Although Newton's laws described the physical universe and did so by setting forth regular and orderly laws, but he did not want to suggest that everything could be explained by mere mechanics:  "Gravity explains the motions of the planets, but it cannot explain who set the planets in motion. God governs all things and knows all that is or can be done.” 

*However, many people would, partly as a result of Newton's work, come to view the universe as regular, orderly, and rational—created by God, but left to run for itself.  The 18th Century would see thinkers who imagined “God the Clockmaker” who built the Universe with set and rational laws, wound it up, and stepped back to watch it work—in this worldview (sometimes called Deism) God was real but not active in people's lives (which undermined many traditional religious views).

*Besides his studies of gravity and motion, Newton also served a warden of the Royal Mint (in which position he helped reform the currency from hand-hammered to machine milled coins—and had at least ten counterfeiters hanged, drawn, and quartered).  He als, studied optics (an important part of physics) and alchemy, which was not then viewed as pseudo-science as it is today.  It is likely that exposure to mercury and other dangerous substances contributed to his death.

*Newton's description of overarching laws for the physical universe suggested to many that there might be similar laws—Natural Law—that would always be valid for mankind, superseding national law, ecclesiastical law, or entrenched customs, which would only be valid if they were based on natural laws.  Exactly what these natural laws were, though, was a subject for debate.

*In England, the turmoil of the 1600s produced two very different bodies of work on political theory:  Thomas Hobbes's Leviathan and John Locke's Essay on Human Understanding and Two Treatises on Government.

*Thomas Hobbes was born prematurely in 1588 when his mother went into labour out of shock at hearing of the approach of the Spanish Armada—Hobbes said his mother gave birth to twins:  him and fear.  During the English Civil War, Hobbes was disgusted and terrified by the chaos, violence, and breakdown of social order, and he conceived a very pessimistic view of human nation.  In a state of nature, he said, men could not control their emotions and came into unchecked conflict, a “war of all against all.”  Life, in such a state, is "solitary, poor, nasty, brutish, and short."  He most famously wrote of this in Leviathan (named for a Biblical sea-creature of great size and power).  In this and other works he described a contract theory of society—men gave up some individual liberty to a strong ruler, who in turn protected individuals against each other.  As long as he did that, the ruler deserved people's unswerving loyalty.  Many people, especially Arminians (who believed in free will and the potential goodness of man) opposed this theory, but strong rulers used it to justify their power.

*John Locke, although also using contract theory, based his application of it on a very different concept of human nature.  He felt that Man is reasonable and, by nature, tolerant (although capable of greed and oppression).  In a state of nature, all people are equal and independent, with natural rights to defend their lives, liberties, health, and property.  Still, their nature is not bad—or good.  Man begins as a tabula rasa, a blank slate, to become good or bad depending on the world in which he finds himself—the ancient Christian notions of Original Sin is rejected.  Therefore, government had an obligation to treat the governed fairly, respecting their rights, or else it would lose the right to their support:  That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it.

*The argument of nature versus nurture was raised and widely debated—are we born the way we are, or does society make us that way?  Is human nature fixed, indeed, are good and bad absolute concepts, or can we accept relativism, that different things may be best in different times and places, and therefore culture can be changed and humanity improved?

*Locke's ideas of life, liberty, and property greatly influenced the founding fathers of the United States (and of the French Revolution).  In fact, Locke even tried to put his theories into practise when he was invited to write the constitution of the Colony of South Carolina in 1669 (although it was never really used).  His constitution would have allowed religious toleration, secret ballots (to prevent intimidation at the polls), and 60-year expirations of laws so old laws would not remain on the books forever (no 400-year old ship money taxes for Carolina).  However, some liberties were limited by the fact that Locke was hired by the Lords Proprietor who owned the colony and wanted to keep power.  Nonetheless, Locke introduced new ideas in the area of natural law, particularly the ability of man to be made better, and many people felt they could improve society, and thus humanity, through reason.  After all, this was the age in which Descartes said cogito ergo sum; it was the Age of Reason.

*The Age of Reason, or the Enlightenment (as those who took part in it viewed themselves as superior to the people of the Dark Ages before them), was a time when ideas ruled society, or at least many of its most influential members, known as Philosophes.  For these people, society should be based on reason, science, natural laws, and things that could be objectively, experimentally proven.  They rejected traditional religious, political, economic, and social views.

*One influential group were the Freemasons.  Although they had traditions dating back to the Middle Ages, these were vague and semi-mythical.  However, in 1717, the Grand Lodge of London was formed to govern all Freemasons in England.  This was a semi-secret society with rituals, traditions, ceremonial clothing, and a commitment to mutual assistance and the spread of rational Enlightenment ideas.  Although Masonry required a belief in god, many Masons were deists, for whom God was the maker of the universe, but not involved in their lives.  Many of America's founders and subsequent presidents would be Masons, as would many other world leaders of the 1700s and 1800s.

*One of the most famous Philosophes was François-Marie Arouet, known by the pen name Voltaire.  Voltaire was a man of many contradictions.  He believed in (and strongly and stridently advocated) the rule of law (rather than tyranny), a free press (partly because he was so often censored, but also on principal—he supposedly told a rival "I disapprove of what you say, but I will defend to the death your right to say it" (although this story was actually made up by a later biographer, it does illustrate his attitude), religious toleration (although he believed the Church was a sham, used to control people through fear of damnation, and that more evil had been done in the name of religion than for almost any other reason), humane treatment of criminals (Voltaire himself was exiled from France without a trial, although it could have been much worse), and government reform. 

*Voltaire praised England's system of government, but he ultimately believed that enlightened despotism was the best system of government, at least for the time being (and if the despots were advised by philosophes like Voltaire—he was a close friend with Frederick the Great, at least when they communicated by letter; in person they always argued).  He held this belief because he distrusted outright democracy.  He thought the French aristocracy was parasitic and corrupt, the middle class small and ineffective, and the mass of common people to be a mob of idiots.  The only good thing he saw about the Church was that the tithe that people had, by law, to pay, always gave people something to be mad about.

*Voltaire was very cynical, and wrote one of his most famous works, Candide, as a satire of optimism (perhaps we do not live in the best of all possible worlds) as well as romantic stories and adventure novels popular in his age.  Candide, an optimistic young man, and his acquaintances endure innumerable hardships and humiliations before finally settling down in an out-of-the-way place to tend their own gardens and make the best of their situation.  Despite his cynicism, many of Voltaire's ideas also influenced the American and French Revolutions.  The Pope, however, banned many of his works.

*Another Frenchman also influenced American political thought.  The Baron de Montesquieu was inspired by the Glorious Revolution and subsequent adoption of the Bill of Rights in England, which took place during his youth.  Later, the death of Louis XIV and the reign of the weaker Louis XV affected his theories as well. 

*He saw two sets of threes in politics.  There were three forms of government:  Hereditary Monarchy, ruled by honour, Democratically elected governments, ruled by virtue, and Despotic governments, ruled by fear—but, said Montesquieu, "government should be set up so that no man need be afraid of another."

*Within a government, there exist three branches, executive (to enforce laws), legislative (to create laws), and judicial (to judge obedience to the laws).  These three branches out to be separate and balanced, but he feared that in France they were not.  In any event, these three branches rejected the Three Estates of the middle ages (and thus France's Estates-General).  Montesquieu was also the most-frequently quoted writer on government and politics during the American Revolution and among the framers of the Constitution.  The Pope, however, banned some of his works.

*Another French writer (and composer), Jean-Jacques Rousseau, wrote about government in The Social Contract, but his view of man was very different from Hobbes's, or even Locke's. Rousseau did not see man as basically brutish, or even as a tabula rasa, to be made good by society.  Rather, in a state of nature, Man is born good (a noble savage), and only becomes bad if he picks up bad habits from society or is enslaved by his government.  All children need is a good teacher to become good adults (an idea he focused on in the book Émile).  All adults need is a government into which they willingly join and which is ruled by the popular will through laws the people make themselves, so that government does not infringe on anyone's freedom.  Rousseau did not want a monarch or even a representative assembly.  He wanted mankind to be free and self-governing (and ideally living in the countryside practising simple skills and crafts).

*The work of French farmers inspired economic thinkers called the Physiocrats.  They believed (contrary to mercantilism) that wealth did not exist in a fixed quantity of gold and silver, but that wealth is created by work—and they focused on agricultural work, where farmers create new wealth with each crop, although they partly focused on this because France had a strong agricultural sector and a weak industrial sector, and they wanted to play to their strengths.  They said, in fact, that countries should produce what they could produce best, and trade that with other countries for what they produced in surplus—no more confining trade within each empire.  Therefore, government limitations on production and trade were bad, because they discouraged the natural flow of trade between people and countries.  Furthermore, left to themselves, people will make what is most profitable, and find the best economic course in the long run, better than a government could.

*In Scotland, the Physiocrats' ideas would be expanded and improved upon by Adam Smith in many books, including The Wealth of Nations, often considered the first work of modern economics.  It discussed the laws of supply and demand, advocated free trade, and admitted that self-interest was behind most human economic effort: “It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity but to their self-love, and never talk to them of our own necessities but of their advantages.”  However, it also  said that competition was good—guided by the Invisible Hand of the Economy, it would force people to improve their products through competition.

*Smith also described early manufacturing and the division of labour in which many unskilled workers could do more cheaply what a few skilled craftsmen once did--One worker could probably make only twenty pins per day. However, if ten people divided up the eighteen steps required to make a pin, they could make a combined amount of 48,000 pins in one day.  Smith's principles formed the basis of the laissez-faire theory of economics—that the government should let the economy alone.

*If Smith invented modern economics, Edward Gibbon may have invented modern history.  Between 1776 and 1788 he wrote the six-volume Decline and Fall of the Roman Empire which was highly popular and highly controversial.  It was very well-written, with clever turns of phrase and an engrossing narrative that describes a great ancient empire that did not suddenly collapse in 476 AD, but that slowly declined over centuries.  It also had a provocative thesis:  Christianity, which turned peoples' loyalties towards the church instead of the Roman Government, weakened the empire (until the Church could pick up the pieces and make itself the main power in Europe-and killed far more Christians in disagreements over doctrine than the Roman government ever did).  This was seen as an historical process, though, not something ordained by God.  He said, "I have described the triumph of barbarism and religion."  However, he also used, as much as possible, primary sources, actually trying to find original documents (or at least copies of them) rather than simply relying on other historians' works.  This is sometimes seen as the beginning of modern historical research.

*Perhaps the greatest literary work of the entire Enlightenment was Denis Diderot's Enyclopedie.  It contained contributions from many of the great philosophes—Voltaire, Rousseau, and Montesquieu, among many others, and set out to fight superstitions while spreading knowledge and discussing what knowledge is.  The Encyclopedie opened up the workings of the known world in a way no one had ever tried to do. It boldly told the average man that he could know what only kings, emperors, and their lieutenants were supposed to know. It suggested that anyone should have access to rational truth, and it classed religion as merely a philosophy barely a step above superstition and black magic. In that sense it was a profoundly revolutionary document, and was banned by kings and popes.  It would also inspire many of the ideas of the French Revolution, as it questioned the social role of kings and popes.