THE simple homily "Save the whales!" began as a plea to stop the harvesting of great blue and other large whales. It was inspired by our first Earth Day 25 years ago. Shortly thereafter, it became a rallying cry for the green revolution

For more than 20 years, the idea was widely supported without question. But does a total ban on whaling make scientific sense? Equally important, do advocates of a ban hold the moral high ground?

Life is much simpler when we think in black and white. With this binary model, there are good ideas, such as the promotion of liberty, and bad, such as the abuse of government's coercive power. But environmental truths are not so simple; they are often scientifically complex and highly emotional.

Complexity and emotionalism can lead to problems, especially when cultural differences collide. Received "truths," such as "we must ban the harvest of whales," become cultural imperialism in green camouflage. The whaling issue illustrates these points and helps us clarify thinking on environmental matters more generally. It shows us the importance of probing the superficial appeal of environmental shibboleths.

The notion "save the whales" is about as precise as "save the birds." There are many species of whales, at widely varying risks of extinction. The largest is the great blue whale weighing up to 150 tons and equal in length to a Boeing 737-200.

The deadliest is Orcinus orca, the killer whale, which often hunts in packs like an aquatic wolf. The smartest is the bottle-nosed dolphin, whose brain-to-body-weight ratio more closely approximates humans' than any other mammal. And then there's the minke, a small, plentiful whale found in many of the world's oceans.

Before we set out to "save" these diverse creatures we should realize three things:

-- Many whales species are far from endangered;

-- There is no a priori reason to assume that hunting individual whales will extinguish an entire species; and

-- We display an arrogant disregard for traditional cultures when we impose the values of our wealthy, highly modernized society upon them. This last point deserves further attention because Western environmentalists often assume their anti-whaling position is the correct one.

In Western cultures, whales had substantial commercial value for several centuries. In the Middle Ages, Norwegians, Britons and Germans hunted whales, chiefly for food. From the 17th to the 19th centuries, whales, especially toothed whales such as the sperm, were hunted primarily for their oil, an important input for lighting and soap-making. ("One candlepower," a unit of light, is defined as the amount of light given off by a pure spermaceti candle burning at a rate of 120 grams per hour.)

The U.S. led the world in whaling during the early to mid-19th century, and many coastal New England towns owed their prosperity to the whaling industry.

In a classic "tragedy of the commons," many species dwindled in numbers and several were threatened with extinction. Since whales were owned only after harpooned and landed, whalers lacked incentives to preserve viable breeding populations. Any whales left could be taken by other whalers. And even if incentives for conservation had existed, scientific information about how to preserve genetically viable populations was sorely lacking. Today, we have better information and know how to create proper incentives.

Current blue and humpback whale populations are indeed low, and some species are endangered. The former Soviet Union's recurrent violations of treaties restricting whale harvests took a heavy toll, but members of some other species are plentiful. An example is the minke whale, which has long played a significant role in the Norwegian whaling industry.

There may be up to one million minkes. In 1994, 32 Norwegian boats killed a total of 279 minkes out of an estimated regional population of 87,000 whales. This rate of about one-third of 1 percent is biologically trivial and has no significant ecological impact. However, to the centuries-old maritime societies that evolved around whaling, minkes are culturally, economically and nutritionally significant. Minkes support these villages much as buffalo supported the late 19th century Great Plains Indians.

Proscribing a total ban on whaling denies cultures time to adjust and ignores the relative abundance of many species. Whatever its environmental and emotional appeal, an absolute ban is cultural imperialism. Can members of "Save the whales!" organizations justify imposing their environmental morality on other cultures? When advocates for a ban ignore scientific evidence that the minke are no more threatened than mallard ducks, their arguments carry a tinge of ethical and intellectual arrogance.

In the end, a total ban on all whaling oversimplifies a complex issue. First, not all whales are threatened. Second, we have the technology to create transferable property rights in whales. With such guaranteed rights, whales will not be hunted to extinction. Third, whales are central to traditions of coastal villages in Japan, Norway, and Iceland. Reasonable harvest poses little threat to the continued existence of these animals. In contrast, insensitive, imperialistic Western environmentalism surely threatens these villages when it imposes its tastes on traditional cultures.

The lessons here are clear. It would be a mark of maturity for the environmental movement if it applied these lessons to the celebration of Earth Day's 25th anniversary.