Does Leibnizs Law Imply That Its Impossible for Things To Change?
Suppose in 1980 we spend a pleasant afternoon sitting underneath a little tree–call it Junior. In 2006 we return to the same location and find a much taller, fuller tree–call it Senior. People living nearby tell us that no tree was ever cut down or removed from that spot. Does Leibniz’s Law allow us to say that Junior and Senior are one and the same tree? It looks like the trees have different properties. Junior was little, but Senior is very tall and full. Since they don’t have the same properties, how can they be one and the same tree? Intuitively, we want to say that Junior is the same tree as Senior, even though Senior is much taller and fuller than Junior. That is, Senior is NOW much taller and fuller than Junior WAS. Perhaps this is important. After all, can’t we say: • the way Senior WAS is the same as the way Junior WAS • the way Senior IS NOW is the same as the way Junior IS NOW So we have to pay attention to the time at which things have various properties. Senior isn’t jus
