@kennethamy,
Even in real life, outside of formal debates, very few situations arise in which someone must make a
prima facie case for quoting someone either as illustration or as as part of an exposition of a position. Naturally, if someone is cited in an argument or expostulation, questions about its legitimacy can, and probably will, find their place; but it seems awkward and contrary to demand that a laundry list of such potential questions should be answered before they arise, assuming they arise (which is not always the case) at all.
Unless the debate is carried on, and understood to be so, from within a dogmatic position, very few philosophic discussions seem either begin or end with an appeal to authority that is decisive. The opposite is often true. Aristotle begins the first book of the Metaphysics by citing or discussing other philosophers, but only to show that each only partly understood cause. Aquinas will begin a question by presenting the arguments against which he will demonstrate the contrary. Hobbes, too, used Filmer's texts against which he argued. A great deal of philosophical thinking is triggered by dissatisfaction with a prior account of a problem.