  It is furthermore important to note that potentiality in this discussion throughout excludes actuality. In a formulation closely matching the formulation of the principle of non-contradiction, Aristotle asserts that “some things are the same [=have the same properties, are the same substances] both in potentiality and in actuality, but not at the same time or not in the same respect, as e.g.  [a thing is] warm in actuality and cold in potentiality” (Physics 3.1,  201a19–22).[19]   Hence the ability of Aristotle’s definition  to pick out the paradoxical entity, which is the actuality of a  potentiality that can no longer be present once it has been replaced  by the corresponding property in actuality.