"Thou shalt not exploit what God has made." Those eight words make up my short "church-speak" definition of eco-justice.

I've found the sentence to be helpful on several levels when I'm talking with church groups.

• By echoing the style of the 10 Commandments, it immediately puts us into a way of thinking oriented toward the moral content of our most basic relationships.

• The language about "what God has made" holds together our relationships with all parts of God's creation -- humankind and "otherkind" alike. There's not one set of rules for dealing with people, and multiple other sets of rules for dealing with domestic animals, wild animals, plants, minerals, air and water.

• The really stimulating word in the sentence is "exploit." Applying that word within the sense of a single set of rules is shocking, because there is a long tradition of using the term in dramatically different ways.

My eco-justice definition lumps together both realms -- the treatment of workers and the use of natural resources -- and says that any exploitation is wrong. It is a provocative notion, and one that I've found to be a good conversation starter.

But, realistically, are those two uses of the word "exploit" talking about the same thing? How on earth can the principles that we bring to social justice be applied to our relationships with non-human, and especially inanimate, parts of the creation?

In sorting that out, let's look first at the characteristics of exploitation in the more familiar human context.

Slavery is the most glaring example. One group of people is used for the benefit of another. The labor, creativity, and freedom of the enslaved individuals are used to provide profit, leisure and status for another. It is not a voluntary relationship. Not only are there economic imbalances; slavery requires power imbalances that impose servitude on the oppressed.

Exploitation can be present even when there is a veneer of freedom. Think of sweatshop workers -- whether in urban America 50 years ago, or in 3rd world settings today. Exploitation emerges when people do that work in a setting of forced choice (it is the only job available -- work for a dollar a day, or don't work at all), and where one party (the boss or the corporation) profits far more handsomely than the workers do.

And it is important to note that a worker/employer relationship isn't necessarily exploitative. When there are real options for work, and where compensation is fair, the workers are not being exploited. Historically, labor unions have helped to even out power imbalances and have worked for just levels of pay and benefits. And in many other settings, the work that people do is freely and even joyously chosen, and the rewards are fairly divided among all involved. That sort of equitable relationship is in line with what Adam Smith envisioned in a genuinely "free market" where all parties benefit. It isn't exploitation if everybody gets a good deal.

In the human realm, we see that exploitation is a corruption of what could be a fair, responsible and just relationship. It is grounded in unbalanced power and benefits. So, how does that idea stretch to the treatment of animals, and the management of natural resources?

The key notions are of voluntary and equitable exchanges. Are all of the parties given choice or voice, and do all parties benefit? Those are tough and controversial ideas when extended beyond the human realm, but let me sketch out some applications.

• Some will say that any raising of livestock for human consumption is exploitative. Most people readily will agree that worst forms of factory farming cross the line into abuse and exploitation. In the middle range, animals that are raised in a "free range" setting and in open relationship with others of the same species, that are well-fed and well-treated, and that are killed humanely, are less exploited than those that are caged. There is more sense of choice and freedom, and more balancing of benefits.

• The sustainable and ecologically-sensitive management of a forest can provide benefit to all involved. Humans get timber and other resources, and the forest community is maintained in a vibrant state of dynamic interrelationship, including fire and a diversity of species. Widespread and unsustainable clear-cutting, on the other hand, provides no benefits to the forest, and is exploitative. All the gain is to the humans, and all the cost is to the forest.

• The extinction of species, or the exhaustion of non-renewable resources, is a selfish and unbalanced use that provides benefit only to the immediate human generation. It isn't fair to the creatures who are lost forever. And it isn't fair to the future generations who are deprived of those treasures. At the least, our exploitation is diminished if we use up resources at the slowest possible rate.