In a recent paper Isham and Doering show how it is possible to subsume purely quantum-theoretical aspects of probability by the logical aspects as provided by the topos approach. In this way probability concepts become secondary and derived from the logical, topos-internal aspects.

**Aim**: Give meaning to probabilities also in contexts in which the relative-frequency interpretation is not available.**Strategy**: Replace probability measure with a collection of truth values.-
**Strategy**: Replace probability measure with a collection of truth values. -
**Outcome**: Probabilities interpreted as propensities/potentiality of a given event to occur. The mathematical context in which such propensities acquire meaning is the Heyting algebras of truth values.