  What if one were to consider the evolution of the system concerned in the multi-dimensional ‘configuration space’ in terms of which the wave function must be described? Here the implications of considering particle permutations are encoded in the topology of such a space by identifying points corresponding to such a permutation and thereby constructing what is known as the ‘reduced configuration space’ formed by the action of the permutation group on the full configuration space. As in the case of ‘ordinary’ space-time, some form of ‘impenetrability assumption’ must be adopted to ensure that – in the case of those particles that are not bosons at least – no two particles occupy the same point of this reduced space.Here Bohmian mechanics offers some advantage: it turns out that the guidance equations ensure the non-coincidence of the relevant particle trajectories (Brown et al. 1999). In effect ‘impenetrability’ is built into the dynamics and thus the configuration space approach and de Broglie-Bohm interpretation fit nicely together.