 The difference between substances, events and properties can now be expressed as follows. Substances and events are distinguished from properties by the fact that properties are the kinds of things the instances of which depend for their existence on the particular substance or event by which they are instantiated, whereas substances and events are such as not to depend for their existence on particular instances of properties. And substances are distinguished from events in the following way: events are those property-instantiators that, when they exist through time, are temporally composed of further things of the same category (i.e., events): substances are those property-instantiators that, when they exist through time, are not temporally composed of things of the same category (i.e., of substances) but endure singly through the period.