This article aims to analyse the phenomenon of the diffusion of interpretive paradigms or argumentation models between constitutional courts. This phenomenon involves the importation of parameters - defined here as extra-systemic to a specific legal system - and the use of the comparative method in applying constitutional texts. The main subject of this study is the analysis of the first 11 years of South African constitutional jurisprudence, which is a convenient scenario since a constitutional provision enables the Constitutional Court to 'consider foreign law' when interpreting the Bill of Rights. In fact, this led to the wide use of foreign jurisprudence and legislation (from which were extracted argumentation models, patterns of balancing between principles and sometimes actual normative 'meanings'): in other words, extra-systemic legal inferences. This article shows the existence of several patterns of legal argumentation based on foreign law which were developed by the South African Constitutional Court.