 It seems that this type of infinite descent is less radical than infinite complexity, but some open questions remain. For instance, is the type of infinite regress at hand innocuous or vicious? Can we capture the difference between metaphysical foundationalism and metaphysical infinitism in terms of the non-viciousness or viciousness of the regress (Nolan 2001; Bliss 2013)? We will leave these issues open, but to improve on the toy example, we might briefly discuss a more concrete case. Sometimes the Nobel Prize winner Hans Dehmelt’s (1989) model is mentioned as a potential example (Schaffer 2003, Morganti 2014, Tahko 2014). Dehmelt speculated that there could be a quark/lepton substructure beyond the known level of quarks, based on the model of the triton, the nucleus of hydrogen’s radioactive isotope tritium: 