The Enlightenment was a phenomenon that began in rational debate and discussion but soon had much more-wide ranging implications. Here are some key achievements of the Age of Reason.

Science

The early achievements of the Enlightenment lay in establishing the laws of scientific investigation. There were several chief architects of these, perhaps most notably Galileo Galilei and Isaac Newton.

Galileo was an Italian astronomer and physicist famous for his astronomical observations. He championed heliocentrism (where the Earth and the other planets revolve around the sun at the centre of the Solar System).

This belief led Galileo into direct conflict with the teachings of the Church and ancient astronomers such as Aristotle amd Ptolemy – which claimed the Earth was the centre of the Universe.

Many later scientists – including Stephen Hawking and Albert Einstein – refer to Galileo as the founder of modern science.

English polymath Isaac Newton was another key figure in the Scientific Revolution, best known for drawing up the laws of gravity. Like Galileo, he is often regarded as one of the father figures of modern science.

It’s thanks to figures such as Newton and Galileo that we have a scientific method to follow – one based on rationality, reason and observable fact.

Revolution

The Age of Enlightenment caused trouble for the monarchies of Europe. As people around the world embraced the idea of life, liberty and happiness, the thought occurred that the powers that be were giving them a raw deal. Philosophers such as Montesquieu advocated a system of government in which power was no longer concentrated in the hands of one man.

When England restored its monarchy in 1660 the returning monarch Charles II first had to promise to rule in cooperation with Parliament.

28 years later in 1688 England expelled King James II and replaced him with William of Orange. William, however, had dramatically reduced powers and had to work very closely with Parliament.

In France it seemed as if the Enlightenment had actually been put into practice as the teachings of Descartes, Voltaire, Rousseau and Montesquieu formed the intellectual backbone of the Revolution, which saw the removal of a monarch and the establishment of a new republic. However, it wasn’t long until this new world descended into brutal despotism and terror.

In America, following the American Revolution the thinking of John Locke and Charles Montesquieu heavily influenced Thomas Jefferson’s proposed philosophy of human rights in the Declaration of Independence.

On the other hand, other rulers such as Frederick the Great embraced the Enlightenment and actively supported artists and thinkers such as Voltaire. While he forged Prussia into a major state he set himself up as a living embodiment of Voltaire’s vision of an enlightened monarch.

Religion

For centuries the Catholic Church had dominated life in Europe, but now it had to watch its step. The Reformation had already eroded the power of Rome, and this new scientific and intellectual revolution presented another major challenge.

The big problem for the church was the concept of Deism espoused by thinkers such as Voltaire and Descartes. This world view thought of the world as being the creation of an all-powerful divine being.

However, this God did not involve himself in the day-to-day operations of the world. Instead, he had simply created the universe and left it to its own devices.

Deism represented a handy compromise. On the one hand it allowed people to embrace the new age of reason and rational debate; but on the other it made space for a God. The problem for any established church was that this new ‘absentee landlord’ version of God left them less significant.

Their initial reaction, therefore, was to retaliate. They pressed governments to ban the works of influential thinkers. In the end however, despite their best efforts, the Church of Rome was forced to accept it no longer dominated the lives of individuals.