It’s easy to say “X is uncertain”. But this doesn’t preclude the statement “X is more likely than Y”.

So, “X is uncertain” is a stupid reason for betting on X versus Y; at least in the absence of commensurately good payoff odds. (In which case it maybe gets more complicated, see win-the-lottery-utility)

Similarly, it’s easy to say “actions X and Y both have pros and cons”. But this doesn’t mean that you should have no preference over choosing action X to action Y.

Eliezer Yudkowsky uses the phrase “the Fallacy of Gray ” to refer to arguments like this:

  • “You can’t be sure of …"
  • "No one’s perfect.”

Fallacy of Gray reasoning can lead to complacently maintaining the status quo and failing with abandon.

For instance,

  • Suppose you were on a diet. And then you broke it. Then you might say “well, I guess I broke my diet there is no more point in eating healthily any more”. (still bad)
  • I don’t know that this other career would be better than my current career, so it doesn’t matter if I switch.