 According to Ehring, this is not true. To see why not, he asks us to consider the following simple scenario: a property-instance at t1 is causally responsible for an instance of the same property at t2. This is a case of causation which is also a case of property persistence. But what does property persistence involve? According to Ehring, property persistence is not just a matter of something not changing its properties. For, even in cases where nothing discernibly changes, the property instantiated at t1 could nevertheless have been replaced by another property of the same type during the period between t1 and t2. To be able to ontologically explain the scenario, therefore, we first need an account of property persistence able to distinguish ‘true’ property persistence from cases of ‘non-salient property change’ or what may also be called property type persistence. But, Ehring claims, this is something a theory according to which property instances are states of affairs cannot do (this he demonstrates with the help of a number of thought experiments, which space does not allow me to reproduce here, but cf. Ehring 1997: 91ff). Therefore, causation gives us reason to think that tropes exist (for more reasons to prefer tropes as causal relata, cf. Garcia-Encinas  2009).[39]