Change can be in the internal or intrinsic properties of a thing, or in its extrinsic relations to external objects, its dispositional properties like its coordinates. The primary view of change is a real, metaphysical change in a "thing itself." Some metaphysicians argue that this must be a change of identity. But this is wrong, because modest changes in the material substrate or the information content (shape and form, internal and external communications) do not an essential relative identity over time of an object.

Because of motion and microscopic physical events, all material things change in time. This is the idea of the Heraclitean "flux" or Platonic "Becoming."

Change means that the concept of "perfect or strict identity over time" is fundamentally flawed. Even in the case of a hypothetical completely inert object that could be protected from loss or gain of a single particle, its position coordinates in most spacetime frames are constantly changing. All the other objects in the universe are changing their spatial relations with the object.

Perfect identity over time is limited to unchanging ideas or concepts – Parmenidean "Being." These are some of the abstract entities, like numbers, simple universals, and logical truths.

The Eleatic followers of Parmenides, notably Zeno, invented his motion paradoxes – the Arrow, Achilles and the Tortoise – to deny change. Zeno's motion paradoxes and claims denying a plurality of beings – that "all is one" – still appear in elementary metaphysics textbooks.

Aristotle's hylomorphic theory of change argued that what persists over time is an underlying substrate (ὑποκείμενον), which he identified with matter (ὕλη ). This is his anticipation of the conservation of mass (now including energy).

But as with the puzzle of The Statue and Lump of Clay, Aristotle knew that the form (μορφος) is an equal contributor to the essence of a substance (οὐσία).

The term “substance” (οὐσία) is used, if not in more, at least in four principal cases; for both the essence and the universal and the genus are held to be the substance of the particular (ἑκάστου), and fourthly the substrate (ὑποκείμενον). The substrate is that of which the rest are predicated, while it is not itself predicated of anything else. Hence we must first determine its nature, for the primary substrate (ὑποκείμενον) is considered to be in the truest sense substance.

Now in one sense we call the matter (ὕλη ) the substrate; in another, the shape (μορφή); and in a third, the combination Both matter and form and their combination are said to be substrate. of the two. By matter I mean, for instance, bronze; by shape, the arrangement of the form (τὸ σχῆμα τῆς ἰδέας); and by the combination of the two, the concrete thing: the statue (ἀνδριάς). Thus if the form is prior to the matter and more truly existent, by the same argument it will also be prior to the combination.

(Aristotle, Metaphysics, Book VII, § vii)

In other cases, a patient is "informed," by perceiving a form. A perceiver thinking about something acquires the form without the matter. Acquisition of the form is by impressing that form onto the material brain, embedding the information as an experience that is recorded (ERR).

At each instant then, there is a new temporal part analogous to all the independent spatial parts. This analogy is severely flawed by an information analysis. Spatial parts have no essential (or accidental) properties in common. The information content can be arbitrarily different. The information content of successive "temporal parts." on the other hand, will have a high degree of identical information.

There will of course be some properties that change with time and others that persist.