AFRICA is the last place on earth where man en masse can still be seen in his romantic role as a force of nature -- basically arbitrary and only superficially malleable. For the expatriates who constitute Patrick Marnham's "invasion," life in such a unique continent can be heady. The profound sense of individuality a westerner's culture teaches him to expect, but never really provides, is his at last. He is rich and superior, yet extremely vulnerable -- as the whites of Shaba and Rhodesia know only too well.

This collection of essays written by Marnham, a British correspondent who has frequently visited and written about Africa since 1973, is refreshing in that he takes the view that we should let Africa get on with things in its own way. Developed nations have consistently treated Africa as the village idiot. But the village idiot is not as dim as he seems. The community can stop pulling him out of the village pond every time he goes for a swim. There's no need for a collection to buy waterwings. Left to himself he'll survive happily with the minnows and the ducks.

A quotation from Joseph Conrad's Heart of Darkness is almost obligatory these days for books on Africa, and Marnham has used this one for his title: "The high stillness confronted these two figures with its ominous patience, waiting for the passing away of a fantastic invasion." His essays, which provide an account of the relationship between the "North" (i.e. the developed nations of east and west) and Africa between the Sahara and the Limpopo, he has divided into three sections. The first deals with East Africa and what he sees as the foolish and damaging irrelevance of game parks, the second with West Africa, wherein is displayed "the phenomenom of Northern aid and development as a form of warfare." In the third section, which deals with what he calls "Parallel Africa," he "examines the often secret resistance put up by the new countries of the entire continent to this implacable process of interference."

The essence of Marnham's viewpoint is probably best conveyed in the book's first section. In East Africa the white conservationists took possession of the land through game parks, making them a beautiful luxury. But for the African who, the author says, fashioned this habitat the land was a necessity. He did not seek to control it, only to survive in it; and if necessary he was prepared to accommodate himself to it. "The conservationist," says Marnham, "wants his African landscape to resemble the world he found when he arrived; his guilt at the destruction that Northern activities entail can be soothed, so long as this ornamental scene exists, undisfigured, as he supposes, by use." But when the dam breaks under the pressure of demand for land, Marnham points out, the destruction of the fauna and their habitat will be greater than if the conservationists had never interfered with the natural balance.

In West Africa Marnham runs over some familiar ground. A quotation from Bertolt Brecht sets the tone: "Famines do not occur. They are organised by the grain trade." There is the often described scene (now gone, incidentally) of the freighters carrying cement and other overordered commodities anchored by the hundreds off Lagos; the World Health Organization ratcatcher who at vast expense fails to catch rats but is nevertheless an integral part of a campaign to roll back the Sahara desert by 1982; and the U.S. AID official intent on bringing supermarkets to a country that can scarcely grow an ear of wheat. He "was making a desert out of a Savannah and calling it development," says Marnham, amending Tacitus.

As for the "often secret resistance" to Northern interference dealt with in the third section, the examples Marnham supplies point mainly to the success of Africa's rulers in replacing colonialism with their own brand of authoritarianism. It is the slaves who make the tyrants and not vice versa, as the 19th-century French dictum explained; and the natural balance in Africa is composed of innate despotism in equal measure with the symbiotic relationship between man and beast that supposedly existed in pre-game park Kenya.

The leave 'em along theory advanced by Marnham is attractive only if you believe that Africans want to be left alone. The truth is that they do not reject the "North"; they parody it. It is not the invaders who are fantastic; it is the invaded. The distortions of the African psyche are caused by the clash of two world, both of which he wants. There may have been "ominous patience" in Conrad's Congo, but in much of the rest of the continent it is perpetual carnival time; carnivals of democracy, religion, commerce, even of police states. Of course, at the same time, the African clings to the simple, understandable realities of his own cultures, and he knows that what the developed world has given him are merely extraneous additions to his own manufacturing capacity. But that does not alter the fact that more Africans use Kalashnikov rifles than use assegais and that the radio has supplanted the tom-tom. There may still be havens left in this world, but it is not possible for a whole continent to sound the general retreat.