>...his state of harmony depends entirely on his harmony with his surroundings

That's how I read the parent article though - not that you should float around in a happy bubble, oblivious to the outer world, but rather that you should 'greet each new day with a smile'; that is, good and bad stuff will happen regardless of what you do, but your reaction to it is what determines how you feel about it. This is not to say that the individual is completely self-sufficient, but rather that one can strive to maintain ones mental balance regardless of what's going on.