The episode of Chauntecleer's dream found in Chaucer's "The Nun's Priest's Tale" is a controversial topic for Chaucer critics. Some critics argue that the downfall-escape experience of Chauntecleer is worthy of investigation because animal figures in fables symbolize people (Finlayson, 2005, 495) and thus their rise and downfall sometimes allude to certain theological or philosophical issues such as the original Fall of Adam and Eve (Payne, 1976, 211-112).Other critics propose, on the contrary, that the episode of Chauntecleer is a "joke" and therefore should not be overestimated (Eliason, 1972, 172). These two opposing perspectives have their own rationale; nevertheless, the centrality of Chauntecleer's dream to the narrative of "The Nun's Priest's Tale" is hard to ignore. Considering the philosophical reverberations of the tale concerning the medieval concepts of destiny and free will, this paper argues that the Chauntecleer episode is not a "joke" but a philosophical exemplar that proposes the absence of any demarcating lines between destiny and free will, bearing in mind that destiny refers to the many options decreed by the deity to be available in every single situation for each individual, while free will refers to humans' freedom to decide what to say and do. The paper contends that Chauntecleer's dream shows how free will and destiny-though they are "inconsistent" forces (Boethius, 1785, 195)-mysteriously connive together to form what can be called conditional free will.