"We speak erroneously of "artificial" materials, "synthetics", and so forth. The basis for this erroneous terminology is the notion that Nature has made certain things which we call natural, and everything else is "man-made", ergo artificial. But what one learns in chemistry is that Nature wrote all the rules of structuring; man does not invent chemical structuring rules; he only discovers the rules. All the chemist can do is find out what Nature permits, and any substances that are thus developed or discovered are inherently natural. It is very important to remember that."