Secundum Veritatem
The Reformed school is able to justify its emphasis upon the iudicium Dei secundum veritatem through the application of the principle of the unio mystica between Christ and the believer, as well as the federal relationship between them, so that the alien righteousness of the former may be imputed to the latter. The absence of a corresponding principle or federal basis within Lutheranism leads to a weakness at this point, with justification tending to be treated as a legal fiction.
Alister McGrath. Iustitia Dei: A History of the Christian Doctrine of Justification - 3rd Edition (Cambridge, UK: Cambridge University Press, 2005), 271