Objects and Identity

In fact, physical objects are a special case. A physical object has only one instance, which progresses through a series of versions—in other words, through an unbranched tree. A physical object also has a single growth point, for which the agent might be said to be time, or physics.

Since physical objects are the ones we're most familiar with, it's only natural that our thought and language should be adapted to them. However, that adaptation gets us into trouble sometimes. Of course it causes confusion when we have to deal with information objects, which is what got me to write about persistent objects in the first place. It can also cause confusion, though, when we try to think about certain situations involving physical objects, and it's those situations that I want to write about here.