A defense of McTaggart

This argument is valid:

1. An object that really changes from being F to being G first exists at a time at which it is F and then exists at a time at which it is G. (Premise)

2. An object that exists at a time t is present then and not purely past. (Premise)

3. Suppose O changes from being present to being purely past.

4. If O really changes from present to purely past is real, then O first exists and is present and then exists and is purely past. (By 3)

5. O does not exist when it is purely past. (By 2)

6. So, O’s change from being present to being purely past is not real change.

In other words, change from present to (purely) past is Cambridge change. And the same argument goes for change from (purely) future to present. So, nothing really changes with respect to being past, present and future. That much McTaggart was right about.