Evaluation of the arguments over quality of permission as Kashef and Naqel in contracts made under duress

Well known Imami jurists see the contracts made under duress
ineffective and believe that the accuracy and effectiveness of such
deals is subject to the permission of the person that has been under
duress.
Thus, a group of these jurists believe that the expression of consent
the effectiveness of the deal starts from the time that permission is
issued and technically this permission is called Naqel (vehicle).
On the other hand, some others (of well known jurists) maintain
that permission makes the transaction effective right from when the
beginning. This is technically called Kashef (revealer). Of course,
those who believe in the latter disagree on how to choose it.
In this paper, the literature on jurists's arguments regarding
contracts made under duress is reviewed and by introducing the applied
advantages of "Kashf' and "Naql" and the types of Kashf the
researcher has investigated the important viewpoints using the credible
sources in Fiqh and also the views of Shiite's jurists.
Contrary to the view of recent specialists the writer has finally
come to the conclusion that permission is effective only if it is of the
type of real Kashf.