They know you can get people to do ridiculous things, like part with their money or give their lives, for ideas that make no sense at all. When anyone arouses these emotions in you, he has you under his control. Seduction is a perfect example. Swindlers arouse greed. Politicians arouse greed.
Preachers arouse fear.
Emotions come from the so-called subconscious mind. The subconscious is crazy. It allows others to program it. We program it ourselves in periods of high emotions. Most people run on emotions.