Everybody's complaining about our post-truth society and fake news. Implicit in such complaints is the idea that truth is a binary thing - that claims are either true or false. In many cases, though, this is not the case. Many things can be true, but useless or even downright misleading. Instead, there is a zone of imprecision, an area where statements are more or less reasonable. It is this domain that investors must live in, and make themselves comfortable with.