ON 29 December 1675, King Charles II of England issued a Proclamation for the Suppression of Coffee Houses.

He’d had it right up to the top of his vast wig with the Peace and Quiet of the realm being disturbed by Idle and Disaffected Persons hopped up on proto-espressos.

Looking back, perhaps he was right.

In 1675, the number of coffee houses in London was roughly 2,000; today that’s the number of London baristas who said “Chocolate on top?” in the last minute.

We’ve reached saturation point.

Back in 17th-century England, King Charles wasn’t the only person who thought coffee was a social vice.

The Women’s Petition Against Coffee of 1674 claimed all-male coffee houses were responsible for “a very sensible Decay of that Old English Vigour .

. .” by promoting “the excessive use of that Newfangled, Abominable, Heathenish liquor called Coffee, which...has so Eunucht our Husbands and Crippled our more kind gallants they come from it with nothing moist but their snotty noses, nothing stiffe but their Joints...” But, to the disappointment of those petitioners, Charles bottled it.

Two days before his proclamation was due to take effect, he backed down, fearful that his head might go the way of his executed father’s - such was English fury about the suppression of an institution that had created the nation’s first egalitarian meeting places, the so-called “penny universities”.

The debate about coffee’s merits has raged ever since.

Is it a pernicious brew that causes impotence, arterio-sclerosis, heart failure, indigestion, insomnia, premature old age, pancreatic cancer, birth defects and bad breath, as well as poverty among the farmers who grow it? Or is it an inky nectar that helps prevent Parkinson’s, Alzheimer’s, liver cancer, gallstones, type 2 diabetes and colon cancer, improves motor skills and reaction times, promotes fair trade to the impoverished south and stimulates both intellectual acuity and social interaction? The answer is, according to a new book of essays about coffee and philosophy, quite possibly all of these.

Coffee: Grounds for Debate, a title in the Philosophy for Everyone series, argues that coffee is a performanceenhancing drug for thinkers.

“The appropriate analogy is that coffee and philosophy go together like foreplay and sex,” insist editors Scott F Parker and Michael W Austin.

“You can have one without the other, but the latter is better with the former and the former often leads to the latter.” Philosopher Basam Romaya says: “With the use of coffee, critical thinking abilities are sharpened, attention to detail enhanced.” This is a venerable claim: in the 16th century, Sheik Abd al Kadir, an Arab scholar, said: “No one can understand the truth until he drinks of coffee’s frothy goodness.” Well, maybe.

There is a big problem for such assertions, namely that coffee (an Ethiopian plant first cultivated in Yemen around AD 575) wasn’t around when some of the world’s leading brains were working at full tilt.

Aristotle never sipped a macchiato, Socrates didn’t have a Caffe Nero loyalty card.

Worse yet, some of the greatest later philosophers - Kant and Nietzsche, for example - were coffee refuseniks.

Yes, Voltaire reportedly drank 60 cups of coffee a day, but not even the most ardent rookie philosophers should copy him.

Costa hasn’t created a nation of geniuses.

The book will also stimulate those seeking to understand the aesthetics and ethics of coffee.

California philosophy professor and self-proclaimed coffee snob Kenneth Davids lists criteria for excellence: 1. Acidity is good; 2. Smoothly viscous or lightly syrupy mouthfeel is good.

3. Aromatic and flavour notes that are complex and intense are better than simple or faded ones.

4. Natural sweetness is good, too much bitterness bad.

5. Natural flavours and aromas such as floral, fruit, honey and chocolate are better than flavours that come from mistakes made during drying, such as mustiness or moldiness.

6. Long, sweet, flavour-saturated aftertastes are good.

7. The robusta bean makes worse coffee than the arabica.

Marvellous - except that many coffee drinkers don’t have the same taste as Davids.

For instance, there is something called the “rio note” - a harsh medicinal sensation apparently created by certain moulds.

Americans like Davids hate it, but it is widely enjoyed in the Middle East and central Europe.

Mmm, yummy - mouldy coffee.

All in all, the debate reminds me of what Homer once said about alcohol in The Simpsons - that it was “the cause of and solution to all of our problems”.

Coffee is like that, only more so.