Substantivalism, Relationism, and Structural Spacetime Realism

A historian of 20 century philosophy of science that were to consider the recent renaissance of studies on the ontological status of spacetime would certainly notice a significant shift of interest toward metaphysical issues previously scorned by neopositivists philosophers. Some philosophers more inclined toward historical analysis have complained about the audacious tendency of some contemporary philosophers of space and time to portray Newton and Leibniz (see Alexander 1956) as defenders of views that, like substantivalism and relationism, do not always represent in an accurate way the positions really taken by these historical figures (see Stein 1967 and DiSalle 1994). However, worse than such moderate forms of “interpretive violence” perpetrated on 17 century natural philosophers – which in any case are not motivated by unfair attempts to add significance to one’s pet philosophical problem by ennobling its historical pedigree – is the fact that the current participants to the debate don’t even seem to agree about how to formulate “spacetime substantivalism” within the fundamental spacetime theory of contemporary physics, the general theory of relativity. For example, it is not clear whether one should identify spacetime with the bare manifold or with the metric field. As is often the case when there is no agreement even about the nature of the problem, there is a natural tendency to affirm that