Two recent contributions to this journal discuss a challenge to Stanford's time-lapse embryo monitoring patent, currently before the European Patent Office (EPO). Sterckx, Cockbain and Pennings (2017) would like to keep the morphokinetics of embryo division in the public domain; they argue that time-lapse monitoring (TLM) is a diagnostic method in the sense of European patent law and therefore unpatentable. In response, Pearce (2017) suggests that the jurisprudence of the EPO unambiguously says that TLM is not a diagnostic method. This commentary proposes an alternative legal ground for challenging patents relating to the principle of TLM, a ground that could be invoked before national courts and, ultimately, the Court of Justice of the European Union: TLM is not a diagnostic procedure but a process of selection that breaches the criterion of dignity in European patent law.