A very wide range of topics that I attempt to bring together, with my great friend The Sage.  (He is always so patient.)  I apologize if I sound a bit shrill, but this is tough stuff to explain and I was straining to do so. We get into the Piraha of the Amazon (who do not use past or future tense, have no word for worry, and do not count), the heart is not a pump, and speech is more than communication.  Do read the fascinating book by Daniel Everett, Don't Sleep, There Are Snakes.