What is the ruling on citing the opinions of others to establish proof and persuade in worldly matters and in interpreting life situations between individuals?

The ruling on what is right or wrong varies according to the issue. For matters related to the infallible revelation, the judgment is referred back to it. As for matters related to people's tastes and customs, provided they do not contradict the Sharia, there is broad leeway, and what most people agree upon is closer to being correct. Therefore, it is permissible to argue for something based on people's agreement in such matters.