first girlfriend. But all these things have some role in the making. The matter is rather like that in classical gravitational theory. Every object exerts a gravitational influence on every other, however far apart.Thus, the nett gravitational force on me is partly determined by a rock on a planet in another galaxy. Of course, since gravitational attraction falls off rapidly with distance, this will be very small, but it is there none the less. So it is with the relations which constitute my quiddity; and the same for other objects. This is quite compatible, note, with the thought that some of the relations of an object are essential to it, and some are not. The relations into which an object enters will change from world to world. If some of these obtain at all possible worlds (or all possible worlds where it exists), they will be essential.

11.5 Emptiness

The view that some things have an essentially relational quiddity is not unknown in the history of Western philosophy.

Consider the disagreement between Newton and Leibniz on the nature of locations in space and time.This can be illustrated by a simple thought-experiment. Suppose that everything were picked up and moved uniformly a kilometre in a particular direction. Alternatively, suppose that all the events in the universe were just as they are, except that they all started one hour later. Do these suppositions make sense?

Newton said ‘yes’: spatio-temporal location would have changed. He was an absolutist about spatial and temporal places. He held that:17

absolute, true, and mathematical time, of itself, and from its own nature, flows equably without relation to anything external, and by another name is called duration.

and that:

absolute space, in its own nature, without relation to anything else, remains always similar and immovable.

In other words, spatial and temporal locations exist in and of themselves, and would be what they are even if there were no physical things that occupied space and time.

Leibniz said ‘no’: nothing would have changed. So the situation described is incoherent. He was a relationalist about spatio-temporal locations. He held:18

17 From the Scholium to the Definitions, Principia Mathematica. See Smart (1964), p. 81.

18 From Leibniz’s third letter to Clarke. See Smart (1964), p. 89.

One: Being an Investigation into the Unity of Reality and of its Parts, including the Singular Object which is Nothingness by Graham Priest