Summary — The Critical Edition of the Opera Omnia of  John Duns  Scotus, initiated in 1950, merited the unanimous consent of experts in the field of the textual criticism of medieval works. Hence, the texts of  the volumes  of the « Ordinatio » (I-VII)  and of the « Lectura »  (XVI-XVIII), up to now published, must be considered as the genuine thought of Scotus. Recently, however, such unanimous  consent  has  been  questioned by V.  Richter,  who  in  a  series  of articles has attempted to bring forth arguments against the authenticity of the two works, without in any way succeeding to discredit the proofs in favour of their authenticity, adduced by the editors. He even tries to distort the testimonies of the codices in defence of his own preconceived thesis. This work, written with the intention of confuting Richter's theories, is nothing else than a necessary clarification of the situation addressed particularly to the scholars devoted to the thought of Scotus who, nevertheless, are still lacking in textual criticism.