The instantiation principle or principle of instantiation or principle of exemplification is the concept in metaphysics and logic (first put forward by David Malet Armstrong) that there can be no uninstantiated or unexemplified properties (or universals).
In other words, it is impossible for a property to exist which is not had by some object.
This broadens the range of properties which exist if the principle is true.
[2] Difficulties for the instantiation principle arise from the existence of truths about the uninstantiated, for example about higher infinities, or about an uninstantiated shade of blue (if such a shade exists).
Those truths appear to be about something, but what can their truthmaker be if they do not in some sense exist?