The Enlightenment, which began in eighteenth-century Europe, is at the heart of today’s modern cosmopolitanism.

If you’re familiar with European history, you’ve probably heard of the period known as the Enlightenment. Sometimes referred to as the “age of reason,” it was a historical watershed moment. Indeed, it profoundly influenced the future development of Western society.

The Enlightenment started in the first half of the eighteenth century and it offered a bracing antidote to the rampant ignorance, terror and paranoia to which society had previously been in thrall.

Prior to the Enlightenment, spells of bad weather were blamed on witches or angry, sky-dwelling gods; oceans and forests were the domain of evil beasts; and scores of people were tortured and killed in the name of religion. It was high time for a change. And thus four main Enlightenment themes began to take shape: reason, science, humanism and progress.

Reason means that there are things in the world that are non-negotiable – that no matter what your so-called sacred text or authoritarian leader says, only reason can dictate the ultimate right. A good example is slavery. Prior to the age of reason, slavery was seen as a fact of life, but as the values of Enlightenment spread, reason shook the foundations of this barbaric practice and eventually helped bring it down.

With the emphasis on science, people began to value knowledge, especially as it pertained to certain universal human traits. Early versions of neuroscience, psychology and cultural anthropology opened the door to humanism, which offered a secular way for people to understand and respect one another. Before this period, religious fervor had been responsible for the bloodbath of the Crusades, and humanism offered a moral footing to acknowledge that genocide and murderous conquests weren’t acceptable.

Humanism also led to what’s known as cosmopolitanism, which can be seen in today’s modern values. Cosmopolitanism is a rejection of tribalism and the narrow-mindedness that pits one group against all others. It looks at everyone as a child of the world and recognizes that just because someone was born in a different country doesn’t mean they’re less deserving of the same rights.