 An alternative approach to the semantics for future contingents is inspired by the works of Leibniz and has been called a Leibnizian semantics (see Øhrstrøm and Hasle 1995). According to this view the set of possible histories is not seen as a traditional tree structure, but as a system of “parallel lines”. On the set of “parallel lines” a relation corresponding to qualitative identity up to a certain instant is defined. In such a model it will be straightforward to introduce truth-values for future contingents.