如果我們相信，從認知對象在存有學上的的差異，可以決定所獲得的認知狀態，並由這樣的進路理解柏拉圖《理想國》中的線喻，便必須先確立出四種不同的存在作為認知對象，分配給線喻中的四個線段，以對這四種對象的存有學解釋為基礎，去理解這個譬喻所要說明的四種認知狀態。然而，這樣的進路將會遇到困難。文中將以陳康、Julia Annas為例，說明這種進路中，很難確定代表各線段的四種不同認知對象各是什麼，而且往往還須回到認知方式的不同來推測對象；此外，這一進路將遭遇下列兩項後果：一是和相同對象可能產生不同認知狀態的事實衝突；另一則是和線喻中間兩線段等長的事實衝突。面對這些困難，文末建議必須透過認知方式去推測、分辨認知對象，以此修正對線喻的解釋。
This article takes the analogy of the Line in Plato's ”Republic” as an example, and deals with the relation between objects and cognitive status. In some important interpretations, scholars (e.g. Ludwig C. H. Chen and Julia Annas) attempt to assign four different objects to four sections of the Line. And, Chen further considers the ontological difference of objects as the basis of epistemology in the analogy of the Line. However, such an approach seems to be improper. For it is difficult to find a consistent assignment of objects for all sections of the Line, especially if we ignore how we reach each cognitive status (represented by each section of the Line). At the same time, it is possible to have the same objects for different cognitive status, and the middle two sections of the Line hold the same length. Thus, a neat ontological assignment of objects might be inconsistent with these two facts. However, if we distinguish the objects by the different methods by which we inquire them, all these troubles will be solved. Therefore, this article suggests that, instead of the ontological difference of objects, it is the different ways of inquiring objects that decide our cognitive status.
