∞ generated and posted on 2016.12.21 ∞
That which is not a direct product of human culture.
Nature, in other words, is something that functions apart from the control that we at least attempt to impose upon the functioning of the biosphere and, indeed, the universe. Though we unquestionably are products of nature, nonetheless a reasonable distinction can be made between that which is artificially created and that which is not, and especially that which is intentionally created, as products of human culture, and that which is not.
Figure legend: What is and is not nature? Clearly that which is not man-made is natural, that is, is an aspect of nature. That which is man created is an artifact, not 'natural', and therefore at least arguably distinct from nature. What about those things that are manmade but not intentionally so? That is, which are byproducts of our existence, such as untreated sewage?
Though the idea of nature is commonly equated with that of biology or biosphere, in fact nature can encompasses both the living and non-living world.