Negative Events: Likelihood versus Gravity of Occurrence

Suppose you pack heat. Someone might ask you, "But what is the likelihood that you, given your cautious and circumspect style of life, will ever be in a situation in which you will need to defend your life, or a family member's life, with deadly force?"

The question is legitimate. The answer is as follows. You must weigh the likelihood of the negative event against the gravity of its occurrence.  Although it may be unlikely that you will need to defend yourself or another with a firearm, the consequences of not being able to do so are dire indeed: death of self or other.

The point is that you must not consider merely the likelihood of negative events, but also their gravity should they occur, when determining courses of action.

For a second example, consider wearing a seat belt. I never drive without seat belt fastened. Given my cautious driving habits, the likelihood of  a serious accident on any given day are very low.  But the consequences of going through the windshield are grave, in two senses of that term.