選言主義在這個論文當中是指在知覺哲學當中的一個特定的理論。它最核心的主張是我們應該拒斥真實知覺與不真實知覺之間所分享的共同性，目的是為了防止懷疑論的攻擊。本篇論文的目的就是為了辯護這種立場的一個版本。 在我討論選言主義之前，我會在第一章先勾勒知覺哲學的議題的大概。在第二章，我會批評三種不同的表徵主義作為解釋知覺經驗的現象特質的理論。在第三章，我會討論麥克•馬丁的選言主義。由於他的立場過於極端，他的理論反對所以共同性在真實知覺與不真實知覺之間，並且蘊含在幻覺情況下，我們是無法知覺到任何的現象特質的。在最後一章，我會說明並且辯護我的立場。我的立場是宣稱知覺經驗具有表徵內容，用來說明現象特質，並且堅守選言主義的立場，解釋真實經驗與不真實經驗的現象特質不是訴諸相同的說明。我的主張看似不太融貫，因為知覺經驗的現象特質若是可以由表徵內容全部解釋，那為什麼還需要外在世界的對象呢。我會在本篇論文中說明為什麼我的主張是融貫的。 / Disjunctivism, in this thesis, refers to a specific position in philosophy of perception. The kernel of disjunctivism is that we should reject certain commonalities between veridical perception and non-veridical perception in order to preserve the relation between our perceptual experience and the world. The aim of this thesis is to defend one version of this position. Before I discuss the disjunctivism, I articulate the problem of perception in Chapter I and criticize three versions of intentionalism in Chapter II. Then, in Chapter III, I reject Mike Martin’s extreme position of disjunctivism. I defend my only theory in the last chapter that consists in the disjunctivists’ main concern that perception is in a relation to the external world (in order to resist the skeptics) and the intentionalists’ insight that the phenomenal character of experience is wholly explained by the intentionality of experience. My thesis prima facie sounds not coherent. It is because if the phenomenal character of experience can be wholly explained by the intentionality, it is not necessary to take the external objects into account. I will articulate why and how my thesis is coherent in this essay.