One moment we are all friends together, different humans sharing a common planet and the next moment the good feelings have melted into suspicious fears.
We have seen this phenomenon with the refugee crisis in Europe; one moment Mrs Merkel is welcoming refugees into Europe to offer them protection and a better life and the offer of sharing these things with refugees; later many Europeans are frightened that so many refugees are entering their nations and while everyone is happy to share what he or she does not have, very few wish to share what they do have.
The phenomenon is publicised by the media. Just as volatility in financial markets is encouraged because speculators can make money when great changes occur, so the media like to exaggerate events and push our minds into dreadful speculations because it profits them so to do.
So we are told one moment that Mr Putin is a great threat to our security and another moment we celebrate Russian co-operation with us in space. One moment we are reminded of our duty to help the helpless, huddled masses and then are warned that millions of Africans will invade our nations, taking what we have and raping us.
Humans have an infinite capacity for hypocrisy and may enjoy both good feelings and suspicious fears about the same topic at the same time.