In Chapter One I considered whether the conservationist is justified in assuming that the current anthropogenic extinction event should be differently evaluated from other kinds of extinction, an assumption that lies behind the belief that current human-caused extinctions ought to be prevented. I found that there are good reasons for supposing them to be very different in kind, reasons that, if biological diversity is valued, give great cause for concern and show that such extinctions are highly undesirable. Conservationists should seek to prevent them, but the prevention measures ought to focus primarily on the provision of opportunities to actively reverse the extinction trend; that is, to allow for speciation.