To put it simply, a man should never wear jeans as a sartorial choice.

   The problem with jeans as casual wear is the fact that they simply should not be classed in such a category. Just like Uggs should never really be considered outdoor shoes, jeans should never be classed as casual wear. Even more of an oxymoron is the idea of "smart jeans" - jeans can never be smart. And the reason for this fact is that jeans were invented, and remain, as work clothes. Like hard-hats, denim is more than fine if you work on a construction site but should you ever really wear them on a night out?

    If you started espousing the virtues of "smart hard-hats", the type which you would gladly team with a blazer to attend an evening dinner,  people would think you have gone crazy. But jeans, designed to be durable but not aesthetically pleasing, seem to be considered acceptable clothing in today's society.

The Boss

   The only exception to the no jeans rule, of course, is Bruce Springsteen who is pretty much a law on to himself. But the main reason that The Boss gets to wear jeans is that they are part of his stage persona, the character who represents the working classes of America, in the same way that David Bowie's orange mullet is synonymous with Ziggy Stardust. As a shorthand for "I sweat it out in a factory/garage throughout the day" jeans are fine - this is the statement they make and it is the statement the Bruce Springsteen character is making too.

   Jeans were invented for the working man and I too own just one pair - from my days toiling in a factory. Yet, even in the Ford factories of the early 20th century, workers would wear jeans to their place of emplyment but would get dressed into their "Sunday Best" for evening events and dinners;  wearing jeans to such things would be considered vulgar from anyone who takes pride in their appearance. The fact that denim trousers has caught on in society as a day to day wear, particularly among those who work in an office sat behind a desk all day, and even odder as formal wear, has to be one of the strangest idiosyncrasies of recent fashion.

Sheepskin Boots For The Legs (Metaphorically Speaking)

   In short, jeans are very much the Uggs of trousers - people who blindly defend Uggs say they wear them solely for comfort factors; although jeans are comfortable too, wearing them is just as odd as wearing Australian farming boots. Unless you are Bruce Springsteen. Then you can do what you want.