In the absence of hard data, we have to take theories as mere hypotheses. History teaches us that to date no disease has been overcome by quarantine measures. Quarantine measures can save time, not defeat the foe.

The Covid-19 outbreak awakens ancestral anxieties. Some of us suddenly perceive our neighbors, friends and families as threats. There is a real risk of violence in the near future.

In the face of any danger, we must first remain reasonable, not rational. These are two very different ways of thinking. We cannot think logically on the basis of incomplete data.

Covid-19 is a hitherto unknown disease which seems to be able to kill up to 1% of the world's population, but which so far has killed only a few thousand people. Researchers are just beginning to study it scientifically. We know that it is caused by a virus that is transmitted through the mucous membranes of the face. No one knows how to prevent its spread, but everyone has their own preconceived ideas about it.

Depending on their culture, scientists have advised the authorities in their countries differently: