Taking office in unjust government

"Taking office in unjust government"in Islamic narrative and juristic books has been recognized as "acceptance of unjust authority".Dignifying cooperation and accepting responsibility in unjust and tyrannical system has been favored by the Shia Fuqaha (the plural of Jurist in Islamic jurisprudence) in general. What remains controversial here is whether accepting a position in unjust governmentassociates with 'intrinsic evil', 'contingency' and 'non-evil' and subsequently 'intrinsic dignity' or 'extrinsic dignity'. Investigating the reasons of 'intrinsic dignity of accepting a position in an unjust government' which comes from the intrinsic evil of that position shows that these reasons fall short of the certainty and proof of the claim. As for other reasons are incapable of proving its permissibility, that is they deserve no judgment on their own and their truth depend on the truth of other topics such as assistance to an unjust and tyrant governor, tenure of office for unlawful and prohibited acts and reinforcing the oppressive government. It seems that taking up positions in the oppressive government is considered contingently evil and prohibited by Sharia law. If it contradicts with another title, it should be subject to the Tazahom (contradiction) rule. In other words, the first principle here is the dignity and prohibition of incumbency in the office of unjust government, unless there are considerations beyond just 'the evil of accepting a position' that justify taking office.