Page "Identity and change" Paragraph 30

Many philosophers strongly oppose this view.

For if this argument works, then any property that has changed from the last time we looked at a thing would mean that the thing does not exist anymore, and there is a new thing in its place.

Every little change in every little property would mean the whole thing is destroyed.

Suppose we look at S1 just a couple of years after it was built.

If just one plank has been replaced, will we say that the ship is a different ship?

Many philosophers would say surely not, as would common sense.

But the ship that is floating on the ocean for a couple of years does have different properties from the original.

Leibniz's Law would have us say that it is a different ship.

One might see all this and conclude, " Well, Leibniz's Law must not be a law at all, but a false claim!

X and Y do not need to have all the same properties to be the same thing.