 Leibniz’s arguments are examples of arguments that attempt to identify something philosophically problematic with absolute time and space. Perhaps more generally, many philosophers have been moved by the idea that even if absolute time and space are not problematic in a way that makes them unacceptable, they are still the kinds of things that we should do without if we can. This kind of attitude can be motivated by a straightforward kind of parsimony—we should always make do with the fewest types of entities possible. Or it can be motivated by a more specific worry about the nature of absolute space and time. You might, for instance, be especially loath to admit unobservable entities into your ontology—you are willing to admit them if you must, but you would rather eliminate them wherever possible. As absolute space and time are unobservable, someone who endorses this attitude will be inclined to think there are no such things.