If you're going to read one ethics/philosophy book (apart from that survey of Aristotle and Kant you probably read in college), Environmental Ethics is a good choice. Rolston explains instrumental and intrinsic value, and surveys different levels of the natural world (individuals, species, communities) for value and resulting duties. The argument that humans have ethical duties to the natural world wanders through different chapters on sentient life, non-sentient organisms, species, ecosystems, and gathers steam as it goes. I haven't read many other ethics texts, so i can't tell if the narrative voice is typical of the genre, but it reminds me of Emerson's dense and learned prose. It's not your typical academic thesis/supporting arguments/conclusion. Rolston explores different avenues, pulling in legal precedents, conservation battles and etymology as he goes. It's almost conversational — a really, really dense conversation with frequent trips to the encyclopedia.

The first five chapters are marvelous, and Rolston gives logic to the feelings that many people have about why we should and do care about (seemingly) abstract concepts like species. The sixth chapter is about value theory, and is filled with diagrams. In 2004 I wrote, "I find this chapter incomprehensible." Still incomprehensible in 2011. The 7th chapter about environmental policy and the 8th chapter about business are perhaps worth reading once, but aren't the best sections of the book. The business chapter in particular hasn't aged well. How many of us are employees of companies that are actively using natural resources any more? It seems easier to identify ethical concerns with working for a company that has toxic waste to dispose of, and harder to judge abnormal energy usage of a server farm. The last chapter is an exploration of what ethics means, practically, and has some interesting things to say about the human capacity for story-telling, and how much richer our stories become when merged with natural history. ( )