‘plagiarisms’ or ‘rivalry’?

 A good question has been set to me: 

Does Marcion actually call the other gospels ‘plagiarisms’ or are you supplying your own translation for the Latin word ‘æmulatio’ which elsewhere in Tetullain does not mean either ‘emulation’ or ‘plagiarism’ but rather ‘rivalry’?

Here my answer: 

this is a typically hermeneutical argument which is based on a wrong assumption. When Tertullian relates the opinion of Marcion he moves away from his own semantic and takes on that of his opponent (when you read the introduction to the reconstruction of the Pauline 10-Letter Collection you will come across numerous examples). Evans, the English translator of Tertullian, knew this, hence he translates Adv. Marc. 4.4, after in 1 the discussion was who had "adulterated" the text of the Gospel, in 2 the "materia aemulatione", rendered correctly as "before anything is done to it", followed by "habuerit de veritate materiam, et Marcionis ante credatur aemulationem a nostro expertum" which he renders: "it had from the truth material, and Marcion's be believed to have suffered hostility from ours before it" - it is about the material (i.e. the text) that has been taken and suffered, what Evans calls hostility, hence injury, alteration (adulteratio) - as the term "plagiarism" was only created a few years before (Tertullian still only knows the term as "kidnapper") - what Marcion criticizes is precisely this, that his New Testament had been taken and hostility done to it, what Martial called plagiatus.