Well John Steinbeck's character Jim Casy (
Grapes of Wrath) said that the holy spirit is that which makes us human. The good and bad in us is all part of the same essence that we all are a part of, as if we share a singularly large soul.
That is a definition in what I believe, in this collective spirit. This spirit that we tap into is all of that which makes up man, animals, nature, etc, however I do not go as so far to say that that is what is holy about it. What makes this the holy spirit is when we choose to work for bettering the lives of others around us, promoting this connection we share. Evil done onto others separates them and that should not be our actions in life.
$0.02