Is this a correct way to think about parody, copyright and free use?

Consider the idea - Should a parody of a copyrighted work generally be considered a fair use?

Works of parody are generally recognized as a form of social criticism that deserve protection under the fair-use doctrine. However, a key factor is the substantiality of copying. This factor will weigh in favor of fair use only so long as the parodist appropriates no greater amount of the original work than is reasonably necessary to conjure up the object of the parody. The Court has noted that a parody , in order to be effective, must be able to clearly "conjure up" the original work. However, the factor will weigh against fair use if the parody takes more of the original than is reasonably necessary to serve the parodic purpose.

a.Yes

b.No