The art of a fair number of those civilisations has been crammed into 10 rooms at the Royal Academy. The curators of "Africa", Tom Phillips and Norman Rosenthal, are entirely unapologetic about the necessary sketchiness of the picture this paints of an entire continent's visual culture. Phillips, who hopes to honour the Royal Academy's tradition of "enlightened foolhardiness", writes of the show in its tombstone catalogue that it is "a sampling of the art of an entire continent" - a phrase bound to raise questions and eyebrows. A "sampling" of the art of a thousand thousand different cultures, drawn from all over one of the largest land masses on the surface of the globe, with a time-span that stretches back from 20th-century South Africa (pierced wooden earplugs) all the way to ancient Egypt (an almost unbearably erotic stone statue of Nefertiti wearing a body-hugging prototype of a Fortuny outfit) - and back, still further back, into the mists of Before Present to a moment in history ("Oldowan Core") when Missing Links were still in the process of evolving into men? What neo-colonialist, neo- imperialist, neo-Victorian presumption. What absurd hubris. Does the man have no shame?
No, he does not, but his other qualities make up for it. Phillips has done his work with such generosity of spirit and largeness of imagination that all qualms are dispelled almost by the time you have passed through the first gallery. Ignore the fake protestations of the heartless professional controversialists who made up their minds about the show before they ever saw it. This is one of the most compelling and extraordinary exhibitions likely to be staged in our lifetimes - and far from being an event rooted in the old kinds of colonialist or modernist or other kinds of appropriationist ignorance, it is one that delights in their exposure. The clockwise tour that begins in Egypt and winds round through Kenya, Tanzania, Zimbabwe, Namibia, Angola, the Congo, Nigeria, Cameroon and finally into Algeria and Morocco - this is both a revelation of the enormous unknown breadth of African art and a demonstration of the fact that it will no longer quite do to consign such art to the wunderkammer marked "Primitive and Tribal".
The cordon sanitaire of "savagery" and "power" that has traditionally been placed round African art is constantly crossed in this show - so it makes sense to start as they have done with the art of Egypt, so formative in the development of the art of Greece and Rome. This is a little nudge or pointer to what lies ahead.
San rock paintings of lithe, red dancers, produced on the Southern Cape of South Africa at around the time when Jesus Christ was born, are among the earliest revelations: testimony to the existence of a tremendously sophisticated but now almost completely unknown society. Their sinuousness is decadent, almost mannered, as Greek vase-painting can be - but that might just be an English art critic "clutching the handrail of Western art" (Phillips's phrase) for reassurance.
Some of the exhibits go so far as to suggest the insolent possibility that African artists may have arrived, rather earlier than artists in the West ever did, at some of the solutions to human representation we commonly associate with the Renaissance. Certain art historians have tried to push the astonishing zinc-brass heads of Ife, in Nigeria, forward to the late 15th century, when they were almost certainly produced during the 12th century or even earlier. It was once thought inconceivable that sculptures of such extraordinary sophistication and such incomparable, quiet realism - they combine some of the qualities of Holbein's drawing with Donatello's modelling - could have been made by someone with no prior knowledge of Western art.
It has been pointed out, inevitably if perhaps a little too vehemently, that - like so much that we now call art - many of the objects in this exhibition started out as no such thing. The early 20th-century Makonde mask from Tanzania, with its mad rabbit ears and beard made of vegetable fibre, is clearly an object denatured by static glass-case museum display: it was originally intended to be worn by the midimu or maskers, who impersonate animal spirits while dancing on stilts during male and female initiation ceremonies. Spotlit on a plinth, it is not quite the same, clearly. But to suggest that it is a thing more denatured by being removed from its original ritual context than, say, any work of 15th-century European devotional sculpture is more than slightly patronising.
It was routine in the West, once, to paint and dress images, to parade them in the convulsive theatres of the pre-Reformation Catholic liturgy. To insist that African art is somehow necessarily more powerfully linked to forms of superstition alien to the modern, rationalist attitude than anything in our own museums is simply false. Such insistence, even if dressed up as a compliment, speaks of a certain nervousness on the part of Western interpreters of African art - a way of attempting to disown the fact that rituals just as opaque to us now as the Makonde initiation ceremonies took place in our own culture not too long ago.
The exhibition is not, however, an experience to be too much moralised over because its chief moral is such a simple and demonstrably true one, proved in the 800 objects it contains. African art is as variously brilliant as any human art. African art can be horrible and terrifying and beautiful and bafflingly direct in its sheer strangeness. It can, sometimes, reprove us with what seems like a closer awareness of the strong, continual rhythms of existence, but we should beware of jumping to too many reassuring conclusions on that score. Although the scholars who have written the catalogue entries try manfully to disguise the fact, hardly anything of any substance is known about the vast majority of the great surviving masterpieces of African art. The cultures that produced it have, in most cases, entirely disappeared and it has been so subject to looting and pillage, climate and termites, that a clear picture of its true history will never be painted.
Halfway through this exhibition you encounter the huge wood-carved Cameroonian figure of an apparently heavily pregnant man, a work that has lingered in the basement of a museum in Berlin, unseen and unknown, for more than half a century. It is clearly a masterpiece, this bug-eyed, fat-bellied vision of some order of experience quite beyond or unknown to us. But what did it mean to the person who carved it? The catalogue tells us that the distended belly could relate to "the (causing and) curing of diseases of the belly"; alternatively, while "there is no need to regard this as an implied hermaphroditism" it might possibly have been intended to indicate "regal embonpoint with a metaphysical dimension". This is a complicated way of saying "I don't have a clue what this thing is, but it is pretty amazing, don't you think" - a sentiment with which most who see it will probably agree. It is, like so much in this triumphant exhibition, an unfathomable but stunning thing. Whoever could have guessed that the Oldowan Core would lead, one day, to this?
n `Africa: the Art of a Continent', Royal Academy, London W1 (0171-439 7438) to 21 Jan 1996
Which objects would have caught the eye of Picasso or Paolozzi?
In the autumn of 1907, on a visit to the Musee du Trocadero with Apollinaire, Picasso encountered African sculpture. He said later: "My greatest artistic revelation came about when I was struck by the sublime beauty of the sculpture done by the anonymous artists of Africa. In their passionate and vigorous logic, these works of sacred art are the most powerful and beautiful products of the human imagination."
He was a year or so behind his Parisian contemporaries - Matisse, Vlaminck and Derain - who were all keen collectors. Now Picasso began to investigate the possibilities of African art, combining elements of his new interest with other influences drawn from the Etruscan, Cycladic and Mesopotamian cultures. The result was the Demoiselles d'Avignon.
This classic piece of Zairean carving (far left) is typical of the angular sculptures Picasso would have seen in Paris, displaying the simplicity of form and lack of realism which he found so appealing.
Epstein met Brancusi, Picasso and Modigliani in Paris in 1912 when he encountered their collections of African art. Building on his interest in Assyrian and Indian art, he also began to collect. The first evidence of the influence of African sculpture on Epstein's art is his Figure in Fleniten of 1913, and his First Marble Venus of the same year exhibits the facial features of a Senufo figure from the Ivory Coast.
Epstein once owned the Mbunda mask on show at the RA. With its convex cheeks and flat features, it forms a good comparison with the head of his controversial sculpture Night of 1928, which was famously vilified in an unwittingly apposite critique in the Daily Express as "a prehistoric, blood-sodden cannibal intoning a horrid ritual over a dead victim".
In October 1921, Henry Moore, then a student at the Royal College of Art, began to visit the British Museum on Wednesday and Sunday afternoons. Here he saw examples of the African carvings of which he had read in Roger Fry's celebrated essay on Negro sculpture, published a few months previously. He had already seen similar pieces in the home of his Leeds professor Michael Sadier - a renowned collector. But it was Fry's essay which really struck a chord.
"African artists," Fry had written, "really conceive form in three dimensions... Without attaining anything like representational accuracy they have complete (plastic) freedom... He [the artist] has also an exquisite taste in his handling of material."
The same might be said of Moore's own gradually forming concept of sculpture. In direct reference to this essay, he later said: "Once you'd read Roger Fry, the whole thing was there." Moore would undoubtedly have known the famous stool in the show, acquired by the British Museum in 1905 and whose simple, tubular arms and overall conception seem to echo much of Fry's enthusiasm, achieving grace and fluidity without the need for anatomical accuracy.
While a student in the mid-1940s at the Slade, which had then been evacuated to Oxford, Paolozzi found relief from the school's interminably conservative curriculum at the Pitt-Rivers Museum, a treasurehouse of African art and artefacts - often very bizarre.
Typical of Paolozzi's early works is Philosopher of 1957 (in the British Council Collection), whose totemic form carries something of the symbolic, mystical qualities of the ritual objects with which the artist had become familiar in Oxford.
This Nkisi (left), a classic Kongo fetish object - a repository of healing forces and made from an eclectic selection of found objects - also echoes the idea of Paolozzi's post-Pop assemblages and celebrated "mechanical men" of the 1960s, in which rusty metal components are transformed into polychrome perfection.
If Henry Moore represents the monumental, calming influence of African sculpture, then it is in Paolozzi that we can see the embodiment of its powerful arcane and ritualistic elements.