The history of coffee shows people have been arguing about the drink for over 500 years

Caffeine is the world's most widely consumed psychoactive drug (you can thank globalization and rough Monday mornings for that).

But before we had a Starbucks on every other block, the drink endured years of prohibition and reinstatements, picking up plenty of advocates and critics throughout its existence.  

In his recently published book, Innovation and Its Enemies, Harvard University professor Calestous Juma highlights the some of the early difficulties that the drink faced when early coffee shops opened. Here are a few of them.

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Coffee started out in Ethiopia, then spread to Yemen and the rest of the Middle East in the 16th century. It was known as "qahwa."

Sufi Muslims started drinking "qahwa" in the early 16th century to stay awake during their evening devotionals. Since both laypeople and clergy were in attendance, Juma writes that people likely brought the drink home to integrate into their daily lives. 

As coffee drinking spread, people started opening "coffee houses," which became centers of interaction for men who didn't have anywhere else to converse about politics and philosophy.

"The preexisting public institutions included the ill-reputed wine tavern; the bathhouse, reserved for the upper classes and lacking in entertainment; and the mosque, which allowed only limited exchanges before and after worship," Juma wrote. "None of the existing social venues at the time allowed for the breadth of social discourse that occurred in the coffeehouses."

But the politically powerful found the drink and the coffee houses that served it threatening.

You might have heard that the French Revolution was planned in coffee houses, where members of the so-called "intelligentsia," the class of political thinkers and polemics, gathered to plot their rebellions.

Coffee houses' potential to facilitate the exchange of ideas and information scared leaders long before the French Revolution. In 1511, Khair Beg, a young governor of Mecca, called for the closure of all coffee houses, fearing they'd be centers of secular uprising. Anyone caught drinking or selling coffee at that time was beaten.

During the 1500s, coffee critics used Muslim drinking laws to defend their claims.

Officials in Cairo, which ruled over Mecca at that time, overturned Khair Beg's coffee ban the same year it was issued. But fear of the coffee houses lingered — some saw them as seedy meeting places, similar to whorehouses. 

In 1535, religious critics pointed to Islam's Hanafi laws, which forbade drunkenness, as a justification to ban coffee again. But whether that concept of "drunkenness" included caffeine jitters depended on which school of Muslim thought you subscribed to at the time.

Two Persian doctors also weighed in on behalf of coffee critics in 1611. Juma writes: 

"The two physicians claimed the beverage was endowed with vile characteristics and said the governor should receive 'great glory and abundant rewards' if he opposed the drink, thus appealing to the governor’s desire for legitimacy and power as a ruler."