This approach includes a subtle update mech-anism on sets of truthmakers, which may in turn inspire new work on the logic ofbelief change.In Chapter 29, arbitrary objects take centre stage. Here, Leon Horsten and RyoIto argue that Fine’s theory of arbitrary objects has an early precursor in Russelll’snotion of variables in his Principles of Mathematics, be it that they differ in theway the dependence relation between variables is treated. This observation goessomewhat against earlier remarks by Fine himself “A Defence of Arbitrary Objects”,and is used as the starting point for an in-depth historical overview of Russell’s workon variables, which may help to revive the philosophical debate on arbitrary objects.
