Scottish economist Adam Smith advocated private enterprise, free trade, and lassiez-faire economics in his classic work popularly known as The Wealth of Nations (1776).

Michel de Montaigne was a French writer who lived in the sixteenth century (1533-1592). He is best remembered for developing the modern essay form. Montaigne wrote short treatments of a wide variety of topics, from historical figures to human nature in general. In his essays, he advocated for rationalism and logical reasoning and demonstrated these traits with the structure and style of his work.

As the Roman Empire was falling apart and being invaded by Germanic tribes, learned monks realized the value of knowledge and the preservation of their Roman ancestry. Since Christianity was the only universally untouchable institution at the time, monks were able to freely transcribe and translate Greek and Roman philosophical texts for posterity.

Erasmus is the most well-known of the Northern Christian humanists. He lived in the fifteenth and early sixteenth centuries and wrote extensively on the gradual reform of society and the importance of peace and reason. He was a devout Catholic, but also unafraid to be sharp in his criticism of the church. His most famous book In Praise of Folly is a criticism of many of the excesses of the church. His second most famous work Handbook of a Christian Knight was written as an educational manual for humanist Christians, advising them how to live practically and successfully as pious humanists.

Sir Thomas More was an advisor to Henry VIII and a contemporary of Erasmus. The two shared ideas about Christian humanism and a dedication to the Catholic faith. More’s most famous work is called Utopia, and it provides an outline of an ideal (some might even say utopian) society.

Johannes Müller, usually referred to by his Latin name Regiomontanus, was a mathematician and astronomer in the fifteenth century. His work trying to situate the positions of various “heavenly bodies” relative to Earth was instrumental in the greater understanding of mathematics and astronomy that would emerge during and after the Copernican Revolution.

James Watt did not invent the telegraph; that honor belongs to Samuel Morse, who also developed Morse Code. James Watt did, however, invent the first reliably functioning and efficient steam engine.

In the late fifteenth century, Italian scholars developed a new form of education that they branded "humanism," which quickly spread across all of Europe and helped ignite both the Renaissance and the Protestant Reformation. The start of humanism began with the rediscovery of Latin and Greek texts, which prompted new ideas and focuses, including a Christian neoplatonism, a focus on the individual, and a challenge to traditional religion.

Adolf Hitler wrote the manifesto, Mein Kampf, or "My Struggle," in which he outlined his political ideology and vision for Germany. The second of two volumes was published in 1926.

Cartesian Dualism was developed by René Descartes, a French philosopher of the early seventeenth century. It states that the spiritual and the material are two distinct worlds and are each subject to their own unique set of laws. According to Descartes, the spiritual word can only be examined through deductive reasoning (developing a theory and then looking for evidence), whereas the material world can be examined through inductive or experimental method.