Webster’s Dictionary defines “Natural” in some of the following relevant ways:

1:  based on an inherent sense of right and wrong

2a:  being in accordance with or determined by nature

8:  ocurring in conformity with the ordinary course of nature

10a:  growing without human care

10b:  existing in, or produced by nature: not artificial

11b:  living in or as if in a state of nature untouched by the influences of civilization and society

13c:  having a form found in nature