Rampancy or wide-spread reputation which is the subject of the research in this article, and which Sheikh Al-Tūsi has claimed to be valid and authoritative by saying: "It is permissible to testify to the endowment, loyalty, emancipation and marriage by way of rampancy (shiyāʿ) such as the property and lineage.  Al-Muhaqiq has followed suit and expressed the same opinion in al-Sharāyiʿ , so has the author of al-Jawāhir. It goes without saying that it appears from the words of our companions, as well as Ibn Qudamah that acquiring knowledge does not depend on rampancy or widespread reputation  or else there would be no room for research in it and disagreement about its instances. Knowledge is a proof in itself in whatever place it is acquired. Yes, it can be said that it is authoritative when it comes to implementing it, but it is not permissible to testify to its content unless true knowledge is obtained.
The main point in this article is to discuss whether rampancy is absolutely authoritative or it is authoritative on the condition of the acquisition of knowledge or strong feeling which is next to knowledge. Apparently, what is meant by rampancy (shiyāʿ), is not merely what is spoken on the tongues of people as we see in social rumors that have no basis. And the apparent meaning of most of the words is that the rampancy itself is a legal argument, and therefore they differed about its instances only, and the chosen opinion is that if definitive knowledge of rampancy is obtained, then it is permissible to act upon it. In fact, if the purport of it is testified and there is a strong feeling (which is next to knowledge), it is authoritative because it is treated as knowledge according to sensible people.
In the event that there is neither knowledge nor confidence and trust, then it is not remote to say that rampancy and reputation in the country is sufficient in the case of genealogies and endowments. And that is based on the completeness of its evidence or from the perspective of absolute conjecture based on the blockage of the door of knowledge; otherwise it is difficult to prove these matters through rampancy in the light of a large number of rulings.