Is it possible to derive new Sharia rulings or jurisprudential principles that have not been stated by any of the earlier scholars, such as saying that the ruling on a specific act differs between Sunnah and obligation depending on the circumstances, or that refraining from an act cannot be Sunnah if the act was deliberate, or considering shaving the beard a prohibited act rather than a disliked one based on the foregoing?

Elaborating on legal rulings or deriving a new principle is a branch of the issue of the authoritativeness of consensus (ijma'). If scholars differ on two opinions, is it permissible to introduce a detailed distinction between them? Scholars have differed on this: some permitted the distinction, some absolutely forbade it, and some made a detailed distinction, stating that it is permissible as long as they (the scholars) have not explicitly declared equality between the issues or if the unifying factor between them does not undermine the consensus.

As for deriving a new legal principle, the fact that previous scholars did not mention it does not prevent acting upon it, unless there was a consensus among them on something that contradicts it. So, if the derivation of the principle does not violate a previous consensus, there is no impediment to it, and its validity then depends on the Islamic legal proofs.