How many blades does a teenager need to shave a patchy beard? Two more than I with my sweet, leathery mug, apparently.

Is this a generational marker, do you think? Or merely one of the glories of this age of unbounded capitalism — the multi-blade disposable razor.

My 18-year-old son went off to university last fall and, to welcome him to dorm living, he was given a "frosh pack" that included several four-blade disposable razors, the Schick Quattro, along with other toiletries. The Quattro is a tool he has grown accustomed to.

I relate this because my son has just begun to shave. Fresh, young bristles sprout out of his cheeks like the delicate shoots of spring. Four blades seem like a lot of scraping power for such a baby face. It's hard not to see him as collateral damage in some kind of shaving arms race.

Gillette introduced its first double-blade razor, the Trac II, in 1971, along with another, lighter product, the Good News disposable razor.

Since then, the choices have exploded. Gillette marketed its three-blade razor, the Mach3 in 1998. Wilkinson Sword and Schick jumped into the game with four blades (the Quattro) in the fall of 2003. And now, even my son's four-blader is obsolete, since Gillette introduced a five-blade razor, the Fusion, last year. Along with a battery-operated version.

The five-blade Fusion, said Gillette CEO James Kitts, is the "future of shaving."

But is it? My Good News handles like a rapier: It's fast and swoops over my cheeks with lighting-quick strokes. But one four-blade razor I tried recently felt like a carpentry tool, or a mini cheese grater. How many edges do you need anyway on something as fair as a man's face?

When more is less

In the Middle Ages, theologians asked, how many angels can dance on the head of a pin? In the 21st century, some of us are wondering, how many blades do you need to shave a grown man's (or a teenager's) beard?

Hasn't any of these shaving companies heard of Occam's razor, the notion that the best solution to any problem should be the simplest. That's what the 14th century friar William Ockham thought and his observation has evolved into one of the foundations of scientific thinking. Doubtful that he would be a four-blader if he were around today.

These devices are not even called razors anymore. They are, in the marketer's phrase, "shaving systems." In the end, what they seem to do is save a few strokes. But they can also strip a layer of skin from your cheeks. You emerge clean-shaven but red-faced.

In the mid-19th century, Karl Marx came to hate capitalism but to herald its astonishing, productive power. The bourgeoisie, who owned the factories, had become a truly revolutionary class.

But the workers of the world haven't united quite in the way Marx (and Friedrich Engels) wanted them to in The Communist Manifesto. Instead, they have taken to their factories worldwide to produce more varieties of face-scraping shaving systems than anybody could ever want.

A torrent of books has been written over the years decrying the false needs required to feed capitalism's voracious appetite.

The latest in this long line of critiques is Benjamin Barber's Consumed: How Markets Corrupt Children, Infantilize Adults, and Swallow Citizens Whole. You get the drift from the title.

But whether we need these products or not, steamroller capitalism gives those of us in the consuming world incredible choice. By one account, 85 different kinds of cookies can be found in certain big-box supermarkets.

Paralyzed by choice

But, hey, aren't we happier in this shopping Nirvana? Not according to the psychologist Barry Schwartz, author of The Paradox of Choice.

Schwartz recounts how he used to walk into a Gap and spend a couple of minutes buying an ill-fitting pair of jeans. Now he spends an hour or so trying on all the different kinds. The jeans he purchases fit much better, but he feels much worse about the entire experience.

So, yes, choice is good — but up to a point.

Schwartz divides consumers into two categories: Maximizers and satisficers.

Maximizers want to make the right decision, every time. They want the best, most perfect pair of jeans offered. They drive themselves crazy.

Who hasn't felt these fits of indecision when faced with 25 varieties of off-white paint or 100 different styles of kitchen tile?

But satisficers buy merely what is "good enough." What that means, for each person, well, that's the problem. But the take-home message is this: The perfect pair of jeans (or job or plasma TV) doesn't necessarily lead to the perfect life.

Here's where philosophy and shopping dovetail. And that's where that most baffling of French philosophers, Jacques Derrida, the master of deconstruction, meets my 18-year-old son while he's shaving his spotty beard.

In the West, the search for perfection has always held a special place. Plato told us about the true, the beautiful and the perfect. The shaving companies boast about "The best a man can be."

But perfection has a dark side, too: The quest for purity.

Penelope Deutscher, in her little Granta book, How to Read Derrida, tells us that behind his almost impossible bafflegab lies a deep suspicion of purity. Derrida is wary of that other phantom of purity — the ideal (down with Plato!).

The ideal torments real, live human beings who are doomed to remain forever imperfect.

And you thought the perfect shave was just an innocent marketing ploy. Actually, in the hands of the French, it has philosophic resonance.

Derrida died in 2004 (just months after the four-bladed Quattro debuted). Perhaps in his toiletry kit he left a double-blade, disposable razor. Though who knows? Maybe he shaved with an old world, straight razor.

He sure is hard to understand, but I sense Jacques Derrida and I are shaving satisficers. Perhaps if he were alive now, he might convince my teenage son he needn't shave with a Quattro. Two blades are good enough.