Reminds me of the &quot;invisible dragon in my garage&quot; analogy from <a href="http:&#x2F;&#x2F;lesswrong.com&#x2F;lw&#x2F;i4&#x2F;belief_in_belief&#x2F;" rel="nofollow">http:&#x2F;&#x2F;lesswrong.com&#x2F;lw&#x2F;i4&#x2F;belief_in_belief&#x2F;</a> :<p>&gt; But now suppose that we say to the claimant, &quot;Okay, we&#x27;ll visit the garage and see if we can hear heavy breathing,&quot; and the claimant quickly says no, it&#x27;s an inaudible dragon. We propose to measure carbon dioxide in the air, and the claimant says the dragon does not breathe. We propose to toss a bag of flour into the air to see if it outlines an invisible dragon, and the claimant immediately says, &quot;The dragon is permeable to flour.&quot;