At least one lesson can be learned from skeptics: clinging passionately to a belief is almost always foolish; the best thing is always serenity, in the face of doubts and certainties. To cling is often to close oneself off, adding to the belief a feeling that time amplifies, to the point where, at the slightest setback, a violent reaction is displayed. At the end, not knowledge, even if it is present, but only emotion manifests itself.