The nose of a mob is its imagination. By this, at any time, it can be quietly led.

Crowds are moved by pictures rather than by arguments. Give a group a vivid image of a threat or a promise and they will follow it, because the thing has already been felt before anyone has had a chance to assess it, and feeling arrives well ahead of evidence. That mechanism is available to whoever understands it, which is exactly why it is worth recognising.

When you notice a strong collective mood forming, look for the picture underneath it. Ask who benefits from your holding that image, and what the same situation looks like set out in plain numbers. Deliberate slowness is most of the defence available.