The modern suit is a riding outfit that kept getting more formal

A one-way ratchet

There is a pattern in men's dress that repeats so consistently it is close to a rule. A garment is introduced as informal, comfortable or practical. It becomes popular. Something newer and more relaxed appears beneath it, and the original is pushed upward into formality.

Every element of what is now considered formal dress arrived this way. Nothing in a modern wardrobe was designed to be formal; it was designed to be easier than whatever it replaced, and then it aged into the role.

The ratchet only turns one way. Garments become more formal over time and essentially never become less so, which is why the most ceremonial clothing in circulation is also the oldest in design.

Riding clothes and the cutaway front

The coats that preceded the suit were long and skirted, and they were a problem on horseback because the front skirts got in the way of the saddle. The solution was to cut the front away, sloping it back from the waist towards the tails behind.

That is where the shape of a morning coat comes from, and the tails of full evening dress descend from the same practical adjustment. Both are riding garments that stopped being ridden in.

The frock coat, cut straight across at the waist with a full skirt all round, was the town equivalent and the standard respectable garment for much of the nineteenth century. It is now essentially extinct, having been displaced by something considerably more comfortable.

The lounge suit was the casual option

What we now call a suit began as a short, soft, unfitted jacket for informal wear — for the country, for the seaside, for lounging, which is where the name comes from. It had no waist seam and hung loosely, which was the point of it.

It was firmly beneath the frock coat in status and would have been unacceptable in serious business or in town. It spread anyway, because it was comfortable and cheap to make, and because the rules relaxed slowly through the late nineteenth and early twentieth centuries.

By the middle of the twentieth century the lounge suit was standard business dress and the frock coat was a costume. The garment did not change status because it improved; it changed status because everything above it fell out of use.

The dinner jacket was an informal dodge

The dinner jacket appeared as a less formal alternative to tailcoats for evenings at home or in a club, for men who did not want to put on full evening dress to eat. It borrowed the short body of the lounge jacket and kept the silk facings of evening wear.

It was, in other words, a way of dressing down. Within a few decades it had almost entirely replaced the tailcoat outside the most ceremonial contexts, and today it is what most people mean by formal evening clothing.

The tailcoat retreated to the narrow band of occasions where it survives. Exactly the same sequence, one step later, than the one that had happened to the frock coat.

What the details still record

The suit carries a good deal of archaeology. The notch and the buttonhole on a lapel are there because the lapel was once a front that buttoned all the way to the neck and was then folded open; the buttonhole had a button to meet.

Vents at the back of a jacket exist so the skirt can spread over a saddle, and the single vent and the double vent are two answers to the same riding problem. Sleeve buttons, ticket pockets and the roll of a collar all point back at earlier and more practical arrangements.

The waistcoat, meanwhile, is the surviving middle layer of what was once a three-part outfit worn in unheated rooms. Its decline tracks the spread of central heating fairly closely, which is as good an illustration as any that clothing responds to buildings as much as to taste.

Where the ratchet has got to now

The pattern has continued. Business dress moved from suits to jackets and separates, then to knitwear and open collars, and the suit is now closer to occasion wear in a good many working lives than it is to a daily uniform.

If the historical pattern holds, the suit will continue drifting upward into the formal band while something currently regarded as casual settles into the space it vacated. That process is already visible and it is not a decline in standards so much as the next turn of a very old mechanism.

It also means the current rules are temporary, as every previous set was. Which is worth remembering whenever anybody explains what one must never wear.