 Now, to endorse this “Undermining” approach, we would have to say that the neo-Lorentzian account is preferable to the space-time account. And, problematically, that looks to be false. The problem is as follows. There’s an explanatory advantage to treating length contraction as explained by geometric features of space-time, rather than by a dynamically occurring process. This, as we see below, will require us to postulate an unexplained brute fact as to why length contraction and time dilation appear in laws governing all matter. Since unexplained coincidences, or treating certain facts as “brute”, is suboptimal (particularly when, as Balashov &amp; Janssen argue (2003: 341–2), the space-time interpretation offers a better explanation—one that does not treat Lorentz invariance as brute or mysterious), so we ought to deny the neo-Lorentzian interpretation of relativity.