 While there are problems with structuralist approaches to the physical, as with the Via Negativa, there is also something right about it. We have noted one idea in philosophy of science that is similar to the structuralist approach to the physical, namely, structural realism. A different idea that philosophers of science have emphasised a lot in recent literature is that physicists and other scientists often construct mathematical models of the systems they are interested in; moreover, they often focus on the mathematical properties of these models themselves (see, e.g. Weisberg 2013). Perhaps a structuralist approach to such mathematical models is plausible. Nevertheless, structuralism about the physical is a thesis, not about these mathematical models, but about the target systems that these models correspond to, and it precisely this that causes the problem.