Yeah, I think that one of the problems is when man starts to think of himself as removed from nature, as though s/he is not actually fundamentally inseparable from it and that man is one thing, nature is another. Earthfully speaking, I see human beings as just as much a product of nature as anything else and in one sense, can't exactly blame him for being the "powerful creature" that he is. But he is part of a living ecosystem called earth, and that's important. It's not *just* about selfishness or not as though man's actions are solitary, though I believe in having values and using reasoning, etc.. But, even for humankind's own sake, it is important to maintain the balance of the ecosystem or humankind will eventually be his own worst enemy (well, actually, not even "eventually" I think). Bears like salmons and it's their nature to eat salmons, and they simply CAN eat salmons and so they eat them as much as they want. But if that's all they ever ate and the situation were a bit different than it generally is, they would kill themselves off if in the process of being their most powerful selves, they ate all the salmons so that there was no more food. It's even in the bear's best interest to be rational.
Something that I see is that humankind seems to think of himself less as a part of the ecosystem, and more as though he is an alien to it who merely governs it in some whimsical and microscopic way (like, I could eat all the fishes if I wanted to - that's how powerful I am!). So, for example, there are sometimes little creatures that are part of a forest's ecosystem who become endangered because of man's logging, and there are households of humans who think it's *crazy* for other humans to be upset about if a certain kind of frog stays alive while loggers and their families don't have a job. I do see the point, but at the same time, it's not truly about frogs or not. It's about what the ecosystem is and the fact that there is a balance that no man knows for sure just how delicate the balance actually is. If the frogs die off, what other creature stops eating and dies off? What kind of chain reaction does that cause? Etc.
The very trait that seems to make mankind feel as though s/he is above and more powerful than nature, humankind's power of reasoning and intellect, is blinding humankind to itself. I believe that mankind's truly most powerful self is in seeing himself as part of the principles which make up our entire ecosystem, as though when s/he looks at himself in a worldwide mirror, s/he sees the whole worldwide view as himself (and knows what to do with it).