No two drugs have defined human civilization the way alcohol and caffeine have.
Nature created both to kill creatures much smaller than us — plants evolved caffeine to poison insect predators, and yeasts produce ethanol to destroy competing microbes....
Alcohol consumption could have given early homo sapiens a survival edge. Before we could properly purify water or prepare food, the risk of ingesting hazardous microbes was so great that the antiseptic qualities of alcohol made it safer to consume than non-alcoholic alternatives — despite alcohol’s own risks....
"The impact of the introduction of coffee into Europe during the seventeenth century was particularly noticeable since the most common beverages of the time, even at breakfast, were weak 'small beer' and wine," Tom Standage wrote in A History of the World in 6 Glasses. "Both were safer than water, which was liable to be contaminated. ... Coffee ... provided a new and safe alternative to alcoholic drinks. Those who drank coffee instead of alcohol began the day alert and stimulated, rather than relaxed and mildly inebriated, and the quality and quantity of their work improved."
"Western Europe began to emerge from an alcoholic haze that had lasted for centuries," Standage quipped.
Coffeehouses became a centerpiece of the Enlightenment — Adam Smith wrote The Wealth of Nations bolstered by caffeine from two fine pre-Starbucks establishments: Cockspur Street and the Turk's Head. Thomas Jefferson called coffee "the favorite drink of the civilized world." Historian Mark Pendergrast told NPR that "the French Revolution and the American Revolution were planned in coffeehouses."
Think I will have a cup of coffee with a splash of Brandy.