Commentary Par XXIV 48

The magister intervenes, not to settle the question (quaestio, a formal exercise in debate in which the answer is known or assumed), but to formulate it – as Peter is about to do.

See Scartazzini (DDP Scartazzini.Par.XXIV.47-48) for a full discussion of the dispute that has followed this verse through the centuries.  And see Tozer's explanation (DDP Tozer.Par.XXIV.46-48): 'The allusion here is to what took place in the mediaeval Universities.  The "Master" is a duly licensed teacher, and the Bachelor a student who is preparing for the office of teacher.  The Bachelor at one stage of his preparatory course was required to pass through a form of examination, which was called "Disputatio tentativa," before a Master, who propounded the subject of this (la question).  Usually in such cases a number of opponents were appointed to combat the candidate's arguments (see Rashdall, The Universities of Europe in the Middle Ages, vol. I., p. 466).  In the present instance, however, this is not supposed to happen, and the proofs advanced lead up to a conclusion which is recognized as well established, so that the candidate has no need [to] terminar la questione.  Similarly, St. Peter propounds the question, and Dante adduces what he considers to be the fitting arguments, but the conclusion is determined beforehand.  The title "disputatio tentativa" is probably referred to in the word tenta in l. 37.'