Abstract
In this paper, I criticize Bedau's definition of `diachronically emergent properties', which says that a property is a DEP if it can only be predicted by a simulation and is nominally emergent. I argue at length that this definition is not complete because it fails to eliminate trivial cases. I discuss the features that an additional criterion should meet in order to complete the definition and I develop a notion, salience, which together with the simulation requirement can be used to characterize DEPs. In the second part of the paper, I sketch this notion. Basically, a property is salient when one can find an indicator, namely a descriptive function, that is such that its fitting description shifts from one elementary mathematical object to another when the property appears. Finally, I discuss restrictions that must be brought to what can count as DFs and EMOs if the definition of salience is to work and be non trivial. I conclude that salience can complete the definition of DEPs