Many have ventured thoughtful explanations as to why development during the past century has been so environmentally destructive. Some natural scientists argue that massive environmental destruction is inevitable when human populations are expanding exponentially. Others emphasize that far too many new substances have been introduced into the environment before determining their impacts on other species let alone ourselves. Economists argue that producers and consumers behave in a manner that cannot be sustained because market prices do not include environmental costs. Moralists argue that people generally are too greedy and shortsighted, while marxists argue that capitalists are too avaricious and myopic. Every discipline has a preferred explanation of our environmental crises consistent with its patterns of thinking. There is no reason to take issue with any of these explanations rooted in particular disciplines of thought for each provides insights.