THERE ARE two indisputable facts about shaving: electric razors only work on the faces of men whose stubble is so thin that they scarcely need a shave in the first place, while wet razors work on all faces but can draw blood and, for reasons so far unknown to science, usually miss a bit.

In theory all men know in their hearts that only the extreme - and for most, unacceptable - remedy of growing a beard offers a way out of the dilemma. In practice they are just as susceptible to hard sell advertising as the women they patronise as fashion victims.

Next week Gillette launches the most glossy and expensive advertising campaign in its history. Eight million pounds will be spent on persuading British men to buy a new razor, the SensorExcel. Wilkinson Sword - Gillette's main rival - will doubtless respond in kind and television screens this summer will be filled with good-looking men having their smooth faces felt appreciatively by equally good- looking women.

The publicity will be breathless. Gillette's new razor is 'revolutionary', 'radical', 'better than the best', 'an outstanding technological breakthrough'.

It is also a pricey product - pounds 3.49 for the razor and then pounds 3.65 a time for packets of five cartridges. The major technical innovation, which justifies the expense, is a skin guard made up of five minute rubber fins which push up the beard hairs so they can be cut lower down the shaft. An unscientific test by the Independent on Sunday's clean-cut staff found it did give a very close shave but was more likely to produce a cut than Wilkinson Sword's less effective 'protector' razor which has a wire safety guard.

Bruce Cleverly, the General Manager for Gillette in northern Europe, whose experience as a US Army intelligence officer will help him in the coming razor war, is certain that men will pay for what he is convinced is a better product.

Cleverly believes there has been a revolution in men's behaviour throughout the West. It is no longer thought unmanly to wear aftershave (perfume by any other name), smear gel on hair and body and spend time and money on grooming every morning.

He may well be right and the four years spent developing the razor at Gillette's laboratories may pay off. But the oddity about shaving is that there are no pop-sociologists ready to back him up with predictions of which way fashions in clean faces or beards are going and what they mean.

Compare this silence with the endless analysis of women's fashion. It is now standard, for example, to plot recessions by looking at the length of women's hemlines or to proclaim what the Paris and Milan collections tell us about the caring Nineties/greedy Eighties or whatever. Indeed, it is hard to see how many fashion pages and cultural studies courses could survive without such expositions.

But on the whiskers men grapple with every morning there is nothing. The gap has been keenly felt. Thorsten Sjolin, author of a 1983 study of shaving for the Swedish Collectors' Association, begins his monograph with the mournful statement 'very little is written about the history of shaving' even though it is, he assures us, 'a very interesting subject . . . and part of our technical heritage'.

His bibliography speaks volumes, or rather does not. He managed to find just eight published works on the subject in America and Europe, including such neglected studies as Antique Shaving Mugs of the United States by Robert Blake Powell (published privately in 1972, Hurst, Texas) and J B Himsworth's authoritative 1953 history, The Story of Cutlery.

The silence is all the more baffling because shaving, when looked at rationally, is a very peculiar thing to do.

Ninety three per cent of men, many of whom are so frightened of going bald they will pay any quack who promises to keep the hair on their heads, shave 15,000 beard hairs off every morning. Over a lifetime they spend six months removing 27-and-a-half inches of whiskers. This year about pounds 80m will be spent on 500 million razors.

That European men have shaved since the Bronze Age raises many avenues of speculation - most, unfortunately, fruitless.

Are beards a sign of virility, as beardies claim? Not really. The Greeks wore beards but the military successful Romans were clean-shaven.

Are beards and long hair a sign that libertarian values are seeping through society? Possibly, in 20th-century societies where they can be seen as a reaction against conscription and the short hair and clean chins of the armed services. But the great Victorian age of European power and moral conformity was also the high point of the beard. From the 1840s to the 1890s beards were almost compulsory. In 1853 even the British War Department was forced, under the pressure of fashion, to allow servicemen to wear them.

The triumph of the beard was buttressed by medical research. Mercer Adam, a Scottish doctor, asked in 1861: 'Why should we shave? Why denude the chin and leave the head intact? Is the use of the razor sanctioned by antiquity, desirable for comeliness, or necessary for comfort and health?' No, it most certainly is not, he replied. The dangers of the razor could clearly be seen by examining the case histories of several men whose health collapsed after shaving off their beards.

This dogmatic 19th-century support for whiskers begs the question whether thick beards - which European and Near- Eastern men can grow but Chinese men, Eskimos and North American Indians cannot - were perhaps an unconscious sign of racial difference in the age of imperialism and white European supremacy?

Alas, no one can get very far with any of this. Mick Cooper, a research psychologist at Sussex University and a specialist on men's studies, said it was impossible to detect any meaning in the decision whether to shave or not to shave across time and across cultures.

Over short periods significance can possibly be read into trends. Since the 1960s, beards have been going out of fashion. Even the craze for designer stubble in the mid-1980s did not affect razor sales, claims Gillette.

You can associate a clean shave with the 1970s reaction against hippies. You can even add that in a recession men are going to want to look as conventional as possible to make sure that they get and keep jobs. But you cannot go much further than that. If it is conventional to grow a beard - just as it is conventional to grow a moustache in the Middle East - then men will strain to do so. Fashion pure and simple without sociological explanations seems to be the answer.

Mr Cooper did, however, offer another potentially offensive interpretation. (Any easily angered beard-wearers should stop reading at this point.) There is now a substantial body of psychological research showing how important good looks are. 'Good-looking' people earn more. As children they are more likely to receive the attention of teachers. If they find themselves in court, they are more likely to be believed by juries.

In these circumstances, suggests Cooper, a beard is an unconscious 'mask' which protects men against the disadvantage of an ugly face.