Well, in one sense we are indeed part of nature, but in another we're not. The word "natural" has many senses in English. Metaphysically, we're part of the natural order. But psychologically and behaviourally, we're alienated from nature in so far as nature is inherently wild. When our species became behaviourally modern, we became terraformers who prefer the artificial to the natural. In that sense, then, we're anti-natural, but not metaphysically supernatural (as I'd put it).