 When we are neither certain that \(B\) nor certain that \({\sim}B\), there remains a range of epistemic attitudes we may have to \(B\): we may be nearly certain that \(B\), think \(B\) more likely than not, etc.. Similarly, we may be certain, nearly certain, etc. that \(B\) given the supposition that \(A\). Make the idealizing assumption that degrees of closeness to certainty can be quantified: 100% certain, 90% certain, etc.; and we can turn to probability theory for what Ramsey called the “logic of partial belief”. There we find a well-established, indispensable concept, “the conditional probability of \(B\) given \(A\)”. It is to this notion that Ramsey refers by the phrase “degrees of belief in \(q\) given \(p\)”.