BOOK REVIEW / Would you buy facts from these men?: 'All There is to Know' - Alexander Coleman & Charles Simmons: Andre Deutsch, 20 pounds

THE Encyclopaedia Britannica is full of remarkable facts, but it will nevertheless come as a surprise to some that the 1986 edition was dedicated to Ronald Reagan. Probably we should not allow this to colour our opinion of what is undeniably a great and famous enterprise. But this odd detail - which in fact does no more than draw attention to the long history of Anglo-American collaboration on the encyclopaedia - points to a striking paradox about the Britannica: why is a work so uncompromisingly devoted to the higher realms of knowledge so well-suited to the wiles of door-to-door salesmen? Hardly anyone would buy a novel or poetry collection from someone who buzzed on the kitchen door with a luxury boxed set in one hand and a vacuum cleaner in the other. Yet encyclopaediae flourish in this setting. If it is true that books do furnish a room, then the Britannica is the literary equivalent of a three-piece suite, with a couple of sideboards and a set of bunk beds thrown in free.

There has not been much of a fuss, but we have just passed the 225th anniversary of the Encyclopaedia Britannica: the first edition was published in December 1768. To mark the occasion, the publishers have produced a handsome facsimile of the original three-volume set. Put beside Coleman and Simmons's bedside digest of the 1910 edition, this bible of ancient learning will be indispensible for anyone wishing to set a historical novel in the late 18th century. But it also offers a nice insight into the ups and downs of the knowledge industry.

The most obvious sign of the times is the modest size of the original book (three fat volumes, compared with today's 32). For some reason, the first book in the original set embraced only the letters A and B; the second accounted for C to L, and volume three handled the rest. Did the editors get tired after the first two letters and think, sod this, let's get a move on? Was it budget pressures that forced them to squeeze half the alphabet into the final volume? Or is there something incorrigibly alphabetical in human nature, which led early scholars to look no further than A or B when they needed names for the major branches of science: agriculture, algebra, anatomy, architecture, arithmetic, art, astronomy, botany, and so on.

Obviously there are gaps in the 18th century's scheme of things: Shakespeare was not fashionable (teachers all over England were boycotting Romeo and Juliet without a second thought); even Homer is not mentioned. But there are a several respects in which the original edition puts later versions somewhat in the shade. The first, predictably, is a matter of linguistic flair and elegance. The 18th century might fall short of our own age in scientific accuracy, but it enjoyed a healthy advantage in poetry. The language of the enlightenment is always going to sound more cultured than our own, and even the tiniest definitions here are gilded by a sweet-witted eloquence which is happy to ascribe riding accidents to 'skittishness', and glad to portray India as a country with 'a vast number of elephants'.

The first editors were not afraid to wrestle with metaphysical terms such as soul - 'a spiritual substance which animates the bodies of living creatures'; or sense - 'a faculty of the soul'. We moderns are too busy for such footling notions, though recent editions have a huge section on sensory reception - 'the means by which an organism is able to react to changes in its external or internal environment'. The 1768 edition attempts a definition for sky: 'the blue expanse of air and atmosphere'. Two centuries of science later, the modern Britannica is lost for words, though there is an entry for skyjacking - 'a form of hijacking'. Our brave new world is also without laughter, which the 18th century knew as 'an affection peculiar to mankind, occasioned by something that tickles the fancy'.

A sober reader might find merely flippant the suggestion that the old lyric habits are superior to our routine modern formulae; but what the original encyclopaedia teaches us is how culturally relative such matters are. In a few centuries' time, today's description of diabetes ('a pathological endocrine condition') might seem charmingly antique compared to the 1768 version: 'the mouth is dry, and the spittle a little white and frothy; the urine being somewhat more than usual, with a small thirst . . . almonds and a milk diet are proper in this distemper, as also wine with ginger.'

The contemporary Britannica is a work of majestic range, but successive editions have purged it of vitality and warmth. And the most striking development of all is not merely aesthetic. We have heard a great deal about Victorian values in recent times, but a single glance at the 1909 Britannica is enough to indicate that when it came to values the Victorian age was a cast-iron low point. There are pious, patronising descriptions of Gipsies - 'they have no ethical principles and do not recognise the obligations of the ten commandments'; the Japanese - 'Emphatically of a laughter- loving nature, the Japanese passes through the world with a smile on his lips'; Greeks, Eskimos, Aboriginals ('the skull is thick and the cerebral capacity small') and many others.

But the entry that truly takes the biscuit is the celebrated essay on the Negro - 'Mentally the negro is inferior to the white . . . the arrest or even deterioration in mental development is no doubt very largely due to the fact that after puberty sexual matters take the first place in the negro's life and thoughts . . . the mental constitution of the negro is that of a child, normally good-natured and cheerful, but subject to sudden fits of emotion during which he is capable of performing acts of singular atrocity . . . given suitable training, the negro is capable of becoming a craftsman of considerable skill, particularly in metal work . . .'

Back in 1768, they were much too civilised to allow pernicious hokum like this to pass as scholarship (what makes it so terrible is that it is so frosty and passionless, so obviously the work of some nocturnal Casaubon proud of his judicious common sense). The first Britannica proves that moral ideas decline as well as advance, by simply noting, with sorrowful candour: 'Negroes are brought from Guinea and other coasts of Africa and sent into the colonies in America to cultivate tobacco, sugar, indigo, &c and this commerce, which is scarce defensible on the foot either of religion or humanity, is now carried on by all the nations that have settlements in the West Indies.'

It is nice to be reminded, every once in a while, that the fantastic advance of knowledge over the centuries has by no means been accompanied by an expansion of our moral and aesthetic sense. The 1768 Britannica claims in its introduction to be utilitarian, but in the end it is happy to be simply useful. Encyclopaediae sway between two extremes: on the one hand they are labyrinthine webs of bizarre facts and amazing stories (this is why Borges loved his Britannica); on the other, they are the symptoms of our deep urge towards order. The fool who wrote about that pompous twaddle about the Negro probably thought he was being cool and rational.

We knew it already, but it is good to remember that values, like unit trusts, fall as well as rise. We have, as we have always had, a straight choice between truth and beauty. All there is to know? Keats would have flipped his lid.