The concept of nationalism emerged as a prominent force in European affairs in the early nineteenth century. People in Europe had long held common and shared national identities, but the rising tide of nationalism in the nineteenth century was of a different order. It threatened the unity of multinational empires such as the Ottoman Empire, the Russian Empire, and the Austro-Hungarian Empire, as people campaigned for the right to self-determination throughout Europe.

Voltaire is the enlightenment thinker who is most readily associated with religious tolerance. Voltaire wrote letters to monarchs all over Europe decrying the insidious impact of Christianity on European society. He believed strongly in Deism and argued that all men were equal in the eyes of God and that all faiths deserved equal respect and merit in a free and open society. Voltaire was widely persecuted in his lifetime for his polemical attacks on the Catholic Church.

Utilitarianism was a philosophy that concerned the morals and ethics of society. It said that the most ethical action was the one that contributed the most good to the most people. This philosophy sought to change morals and ethics to focus of the benefit of actions to society.

Socialism is most often attributed to Robert Owen. He was a political and social philosopher of the 18th and 19th centuries. He wanted to see society turned into a utopia using a specific formula that later became known as socialism.

The unifications of Germany and Italy (both completed in 1871) were inspired by the emergence of nationalism in the nineteenth century. Both countries had long been divided into small states and principalities, yet the people living there retained a shared language and a common heritage. It is generally accepted that the most important characteristic for the formation of a national identity is shared language and a common history.

Charles Fourier and Robert Owen are remembered as early advocates for utopian socialism. Both Fourier and Owen predate Marx, and their version of socialism may be understood as distinct from Marxism. Owen and Fourier advocated for utopian socialism on a very small-scale and communities modeled on their writings arose in France, Britain, and the United States of America in the late eighteenth and early nineteenth centuries.

The enlightenment idea that political legitimacy rests in the “consent of the governed” is most closely associated with the writings of John Locke. Locke is often referred to as the father of modern liberalism. His writings on republicanism, religious tolerance, and the social contract have been widely influential in European and American history. The consent of the governed essentially states that the government only has legitimacy to rule over the people so long as the people accept the government. If the government is deemed deficient, the people have a right and duty to overthrow the government.

Utilitarianism encouraged the government and the Elite to ensure that the greatest number of citizens benefited from the distribution of resources, materials, and profit. This became popular in the Industrial revolution as a middle class developed, the poor got poorer, and there was a surplus of material goods in the economy as a result of factory production.

Hume and Voltaire, in particular, were highly skeptical of the church. Wollstonecraft and Rousseau debated the role of women in society, although neither promoted their subservience. All of the thinkers above were critical of absolutist or tyrannical rule. The Romantics, not the Enlightenment thinkers, valued emotional responses to the world. One of the few things that all of the thinkers above agreed on was the power of human reason.

The Self Strengthening Movement emerged in China in the second half of the nineteenth century. It was a series of institutional and military reforms that were enacted following a humiliating series of concessions and defeats at the hands of European powers.