Edebiyat, farklı coğrafyalardaki dünya görüşlerinin, toplumsal değerlerin, duyguların, düşüncelerin ve imgelerin anlatımıdır. Modern dünyanın edebiyata yansımaları 19. yüzyıldan başlayarak, 20. yüzyılda daha da belirginleşmiş olup; insan ilişkilerinde yaşanılan ayrışımlar, zamanla insanların birbirine karşı yabancılaşmasını da beraberinde getirmiştir. Bireyin yaşadığı yabancılaşma sadece karşısında duran kişiye karşı değil, aynı zamanda kendi benliğine karşı da olmuştur. Bu durumun sonucu olarak bireyin, hem kendisiyle hem de başkasıyla yaşadığı kimlik arayışı edebiyatın en önemli konularından biri olmuştur. Bu konuların ifade edilmesi esnasında yazarlar bazı kavram, imge ve metaforları kullanır. Kullanılan bu kavramların en dikkati çeken, bir kişinin birebir aynı görüntüsünü ifade eden, edebi metinlerde de sıklıkla bireyin yaşadığı kimlik karmaşasını ve yabancılaşmayı anlatmak için kullanılan Alman edebiyatı kökenli “Doppelgänger” kavramıdır. “Doppelgänger”, Türkçede “gölge”, “kötü ikiz”, “ikiz öteki”, “öteki”, “eş ruh”, “ikili kahraman” terimleri ile karşılık bulur.

From times immemorial, literature has accumulated a large and varied store of all kinds of general ideas and conceptions, material and metaphysical, to which the masters have recourse the moment the over-exacting and over-restless human voice begins to be heard. This is exactly the point. Tchekhov himself, a writer and an educated man, refused in advance every possible consolation, material or metaphysical. Not even in Tolstoi, who set no great store by philosophical systems, will you find such keenly expressed disgust for every kind of conceptions and ideas as in Tchekhov. He is well aware that conceptions ought to be esteemed and respected, and he reckons his inability to bend the knee before that which educated people consider holy as a defect against which he must struggle with all his strength. And he does struggle with all his strength against this defect. But not only is the struggle unavailing; the longer Tchekhov lives, the weaker grows the power of lofty words over him, in spite of his own reason and his conscious will. Finally, he frees himself entirely from ideas of every kind, and loses even the notion of connection between the happenings of life. Herein lies the most important and original characteristic of his creation. Anticipating a little, I would here point to his comedy, The Sea-Gull, where, in defiance of all literary principles, the basis of action appears to be not the logical development of passions, or the inevitable connection between cause and effect, but naked accident, ostentatiously nude. As one reads the play, it seems at times that one has before one a copy of a newspaper with an endless series of news paragraphs, heaped upon one another, without order and without previous plan. Sovereign accident reigns everywhere and in everything, this time boldly throwing the gauntlet to all conceptions. In this, I repeat, is Tchekhov’s greatest originality, and this, strangely enough, is the source of his most bitter experiences. He did not want to be original; he made super-human efforts to be like everybody else: but there is no escaping one’s destiny. How many men, above all among writers, wear their fingers to the bone in the effort to be unlike others, and yet they cannot shake themselves free of cliché—yet Tchekhov was original against his will! Evidently originality does not depend upon the readiness to proclaim revolutionary opinions at all costs. The newest and boldest idea may and often does appear tedious and vulgar. In order to become original, instead of inventing an idea, one must achieve a difficult and painful labour; and, since men avoid labour and suffering, the really new is for the most part born in man against his will.