One of the novel topics discussed by Muḥaqiq Nāʾīnī in the principles of Islamic jurisprudence pertains to conflicts – better known as tazāḥum. Before him, the issue of conflict had been sporadically touched on by different scholars of ʿilm al-uṣūl and fiqh but it had not been discussed in detail and a separate chapter had not been dedicated to it. Muḥaqiq Nāʾīnī, however, dedicated a chapter titled "Commanding to something requires that the opposite of it be prohibited" in which he states that no one before him had dedicated such a chapter to this topic. He insists that the scholars before him had ignored this issue despite its numerous benefits. In this chapter, Muḥaqiq Nāʾīnī offers his opinions in three parts: The difference between taʿāruḍ and tazāḥum, the cause of conflict, and preferences in the conflict of two things. He has also mentioned a summary of these discussions in the chapter concerning taʿādul and tarājīḥ. After him, Martyr al-Ṣadr rendered one of the longest discussions on the issue of conflict while touching on taʿāruḍ and tarājiḥ (balance and preferences). On various occasions, he brings up Muḥaqiq Nāʾīnī's points of view and in some cases, he criticizes him. The importance and profuse benefits of the rules pertaining to conflict, as pointed out by Muḥaqiq al-Nāʾīnī, motivated the writer to compare the opinions of the two great scholars and shed light on their differences on the subject-matter. It is to be noted that the function and the benefits of the discussion concerning conflict has more relevant to social and governmental jurisprudence rather than to individual jurisprudence because society and government are in modern time stages on which numerous conflicts of legal rules occur.