Mixing reality and absolute statements seems like a recipe for falsehood.<p>Probabilities work much better. &quot;I&#x27;m 50% certain of A and 50% of not-A&quot;, which means complete ignorance. A &quot;80% A&quot; means you have an opinion, but you acknowledge a 20% possiblity of being wrong. If anybody claims &quot;100% sure of something&quot;, it is an obvious sign of idiocy.