In response to the arguments of Bill McKibben and of Steven Vogel that nature is at an end and that the very concept of nature should be discarded, I argue that the concept of nature is indispensable. A third sense of "nature" besides the two distinguished by Vogel, that of the nature of an organism, is shown, through five arguments, to be vital for environmental philosophy and for ethics in general. It is no coincidence that the same term is used for all three senses of 'nature' in many languages. The indispensability of 'nature' in the third sense is used to suggest the indispensability of 'nature' in the other senses (needed if we are to understand species, to distinguish social systems from natural systems, and to be able to ask metaphysical questions about whether 'nature' in this sense and in the other two might have a creator).