 Ramsey then asserted that for partial belief (i.e. not certain belief) “This amounts roughly to defining the degree of belief in \(p\) by the odds at which the subject would bet on \(p\), the bet being conducted in terms of differences of value as defined”. In making this rough identification then Ramsey draws on the already “old-established” idea of measuring one’s degree of belief in a proposition \(p\) in terms of ones willingness to bet on its being true (1926a, [FM] 172). While he does not elaborate further on this connection it is implicit in the derivations that follow that Ramsey concludes that there is a number \(x\) such that for any option \(\xi\) and any stake \(t\) (positive or negative), \(\xi\) for certain is equivalent to: