There comes a time in a person's life when they want to create a law, and for me that time is now. I have a law, actually it's probably more like a general principle, regarding how people use empirical illustrations. It's fairly common in a conversation for someone to make a statement like this: assertion/ generalization + supporting empirical evidence.
Here's my law: On average, the further away the empirical evidence, either in time or distance, the less valid the assertion/ generalization.
A hypothetical example: If someone says that it's dangerous to swim in the ocean, and they talk about a shark attack that happened that day at the nearby beach, well, that's probably stronger evidence than if they cite an attack in Australia last month.
A real example: I was talking with a friend about spiritual & church things, and he was wondering if the Christian Church was a positive force in the world. We talked for awhile, and he suddenly he bust out: "What about the Inquisition?" I'm not sure how I answered him, but in thinking about it later, I realized that the very fact that he had to go to a different continent and go back in time about 500 years answers his question.
Can you think of other examples?