Consider \(\underline{P}(X)\) as representing the degree to which the evidence supports \(X\). Now consider \(I(X) = 1- (\underline{P}(X) + \underline{P}(\neg X))\). This measures the degree to which the evidence is silent on \(X\). Huber (2009) points out that precise probabilism can then be understood as making the claim that no evidence is ever silent on any proposition. That is, \(I(X)=0\) for all \(X\). One can never suspend judgement. This is a nice way of seeing the strangeness of the precise probabilist’s attitude to evidence. Huber is making this point about Dempster-Shafer belief functions (see  historical appendix,  section 7), but it carries over to IP in general.