In his Yalan (The Lie) Tahsin Yucel interrogates the theme of the lie as an undeniable sign of cultural globalization. As he does so, he exposes the falseness of the world and the identity of the liar that appears in not only university life but also modern media. During this interrogation, the author largely uses data from semiotics, which is also his field of research. He thus establishes the structure of his novel on the binary opposition, to be/to appear. This article aims to study the portrait of the plagiarist by employing certain theoretical definitions provided by psychology and to identify the main causes underlying plagiarism, which is a major theme within the context of the novel.