Pierre Gassendi & herman de vries: I walk therefore I am/ambulo ergo sum

Pierre Gassendi was a french philosopher and contemporary of  Rene Decartes, who clashed with him on the possibility of certain knowledge.

According to herman de vries, an eco-artist and scientist who works with randomness and chance, “descarte’s line cogito ergo sum (i think therefore i am) was opposed by his contemporary gassendi (1592-1655) who lived in digne, a town close to roche rousse [the mountain], with the comment ambulo ergo sum (i walk therfore i am).  people walking up the footpath to the sanctuaire de la nature de la roche rousse will find beside the path this gassendi quote cut into the surface of a rock that once fell from a ridge”. (from John K. Grande, 2004, Art Nature Dialogues, p.232) Note; de vries uses no capitals.