"We trace out the all the fibres of the earth, and live above the hollows we have made in her, marveling that occasionally she gapes open or begins to tremble - as if truly it were not possible that this may be an expression of the indignation of our holy parent!

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     Although earth also bestows medicines upon us on her surface, as she bestows corn, bountiful and generous as she is in all things for our benefit!  The things that she has concealed and hidden underground, those that do not quickly come to birth, are the things that destroy us and drive us to the depths below; so that suddenly the mind soars aloft into the void and ponders what finally will be the end of draining her dry in all the ages, what will be the point to which avarice will penetrate.  How innocent, how blissful, nay even how luxurious life might be, if it coveted nothing from any source, but the surface of the earth" 

- Pliny The Natural History Book 33 I.

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