“[It] appears that we must recognise at least two principal meanings in the word 'nature.' In one sense, it means all the powers existing in either the outer or the inner world and everything which takes place by means of those powers. In another sense, it means, not everything which happens, but only what takes place without the agency, or without the voluntary and intentional agency, of man. This distinction is far from exhausting the ambiguities of the word; but it is the key to most of those on which important consequences depend.” John Stuart Mill, On Nature, 1874
Nature as a term can be inclusive and exclusive. It may include everything in existence or exclude products of human agency (e.g. cities, corn fields, art, technology, pollution) from the rest of the world (e.g. old-growth forest, boulders, elephants, fire, snowfall). The distinction is blurred when we think of tree farms, artificial lungs, and cloned sheep. Many words have dual meanings, but perceptions of nature can influence our place in the world. When nature is viewed exclusively, where does this leave humans?
The city is often considered separate from the natural world. As a remedy, some call for the integration of nature (usually trees) into urban settings. While I consider this a good thing, the terms imply that cities are not already part of nature. When people use these terms, they don't necessarily intend to be exclusive. It just reflects a deeply ingrained idea of nature without a clear alternative. According to inclusive views, cities are no less natural than birds' nests. Both are constructed by animals with material derived from the Earth. This is not a justification for environmental abuse, but simply an understanding of human activity as within the scope of nature.
I like the idea that we are arrangements of atoms -- the same atoms that constitute the world around us. Some arrangements result from human action while others may result from the actions of bears, rain, or geological faults. Fortunately we are capable of conscious decisions, which can and should include a sense of responsibility for environmental well-being.
Perhaps it is enough to refer to streams, flowers, jets, and sculptures individually, reserving nature to describe the whole. All of the examples above are human concepts, and all are composed of material from the (natural) world. If this view of nature is too inclusive to be useful, is there a simple way to distinguish beehives from buildings, ponds from swimming pools, sunsets from street lights ... ?
(Photo of Portland from Adrian's Photo Blog; Photo of Dolly from Next Nature; Photo of Earth from Wikimedia Commons)