These days we can be forgiven for wondering if Homo sapiens have gone completely mad. From just a glance at the headlines, it is easy to conclude that humans are hellbent on destroying themselves and their environment, with little concern for which goes first.

The missiles being heaved across national borders in northeast Asia and the Middle East are the most egregious examples. Less obvious, but every bit as destructive, is our steady degradation of the planet's atmosphere, fresh water and oceans, also known as "the commons."

The key challenge facing these commons, and inevitably all of us who depend on them, is whether humans can learn to see beyond immediate, personal gain and act to preserve the global environment for the sake of our children's children, and beyond. The alternative really isn't an alternative at all. It's simply survival -- or not.

As idealistic as such environmental altruism may sound, it is not totally alien to human societies. The Haudenosaunee people who inhabited North America hundreds of years ago, also known as the Iroquois, are famous for having embraced a philosophy that placed priority on future generations.

Their credo, known as the Seventh Generation Principle, states: "The first mandate . . . is to ensure that our decision-making is guided by consideration of the welfare and well-being of the seventh generation to come."

Recently, this indigenous wisdom has been woven together with contemporary notions of environmental management, specifically the Precautionary Principle, in an indigenous people's declaration known as the Bemidji Statement on Seventh Generation Guardianship. The statement was released on July 6 in Bemidji, Minnesota, at a conference convened by the Indigenous Environmental Network.

However averse we may be to learning from those cultures that we have ransacked in the past, there is much we can discover from their eons of living in dependence on, and harmony with, the earth.

Today we face what has been called "the tragedy of the commons" -- the conflict for natural resources that pits individuals' interests against those of the common good.

According to Wikipedia, the Internet encyclopedia, this term originally comes from a book on population written by William Forster Lloyd in 1833. More recently, the term was popularized by Garrett Hardin in a 1968 Science magazine piece titled "The Tragedy of the Commons."

Various critics have challenged Hardin's claims and assumptions, and Hardin admits that he should have called his essay, "The Tragedy of the Unregulated Commons." Nevertheless, Hardin's commons help illustrate why human societies continue to degrade their air, water and oceans despite the rising costs to health and human welfare that we all inevitably shoulder.

Hardin uses the hypothetical example of animal herders sharing a field. Each herder wants to maximize his own yield and, therefore, will naturally try to increase the size of his herd. With each new animal added to the pasture, there are both costs and benefits: On the positive side, the herder benefits from the proceeds of each extra animal, while on the negative side, each animal contributes to further degradation of the field.

The key here is that "the division of these components is unequal: the individual herder gains all of the advantage, but the disadvantage is shared between all herders using the pasture. Consequently, for an individual herder weighing up these utilities, the rational course of action is to add an extra animal. And then add another, and another. However, since all herders reach the same conclusion, overgrazing and degradation of the pasture is its long-term fate," explains Wikipedia.

In today's world, Hardin's herder represents each of us, each farmer, fisher, politician and corporate CEO who seeks immediate gain at the expense of the greater community, whether it be through abuse of pesticides, overfishing, unnecessary pork-barrel projects or exploitation of workers and natural resources.

Some examples of the "potential and actual tragedies" of the modern commons include, according to Wikipedia, uncontrolled human population growth leading to overpopulation of the planet; pollution of the atmosphere; pollution and wasting of fresh water; soil contamination; logging of old-growth forests; overfishing of the oceans; and species extinction.

More novel examples are littering of public lands, traffic jams, and excessive advertising -- certainly each of us can identify with the time and energy we waste picking spam from between our e-mails. Not a tragedy, of course, but most definitely a waste of individual minutes that, when multiplied, costs society countless millions of hours each year.

No doubt the Iroquois would have some thoughts on how to conserve the time and energy we waste hunched over our computers. However, for the authors of the Bemidji Statement on Seventh Generation Guardianship, conserving nature is the only priority.

"The Statement is written with the intent of being able to adopt it at all levels of our society. It is also written to change the way we think about our future. . . . It is intended for individuals or small groups of individuals to take guardianship responsibility for one piece of the web of life and protect or restore that one piece for this and future generations," reads an introduction to the statement provided by the Minnesota-based Indigenous Environmental Network.

Some readers will find the statement too "green," even quaint, but where it touches on the principle of precaution, it is advocating an approach that is on the cutting edge of environmental policy being made today.

Calling for caution, the Bemidji Statement notes that "scientific uncertainty has been misused to carry out economic, cultural and political exploitation of the land and resources. Failure to recognize the complexity of these relationships will further impair the future health of our people and function of the environment."

Similarly, one definition of the Precautionary Principle -- as contained in the Wingspread Statement drafted in 1998 at a conference of scientists and policymakers in Wisconsin -- states, "We believe existing environmental regulations and other decisions, particularly those based on risk assessment, have failed to protect adequately human health and the environment -- the larger system of which humans are but a part. . . . Therefore, it is necessary to implement the Precautionary Principle: When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of an activity, rather than the public, should bear the burden of proof."

Even more to the point are three distilled elements of the principle offered by Peter Montague, Editor of Rachel's Precaution Reporter, a U.S.-based Precautionary Principle advocacy organization: "When we have a reasonable suspicion of harm, and scientific uncertainty about cause and effect, then we have a duty to take action to prevent harm."

In short, as Earth's human population climbs past 6.4 billion, our degradation of the commons -- our air, water and oceans -- is increasing exponentially; local, regional and global environmental management based on the Precautionary Principle offers a simple and coherent paradigm for ensuring that our own seventh generation has its day in the sun.

As for readers who may think all this precautionary talk is just New Age babble, it is worth noting that abuse of the commons has been on the minds of great thinkers for centuries.

More than 2,300 years ago, the Greek philosopher Aristotle wrote: "For that which is common to the greatest number has the least care bestowed upon it. Every one thinks chiefly of his own, hardly at all of the common interest; and only when he is himself concerned as an individual."

Words to ponder seriously, especially in light of what became of Ancient Greece, and so many other human societies.