The uncanny is a psychological concept which refers to something that is strangely familiar, rather than simply mysterious. It may describe incidents, for example, where an everyday object or act is experienced in an unsettling, alienating, or taboo context. This experience is accompanied by a discomforting effect and often leads to an outright rejection of the object, as in the uncanny valley effect.
The concept of the uncanny was perhaps first fixed by Sigmund Freud in his 1919 essay Das Unheimliche. For Freud, the uncanny's mixture of the familiar and the eerie confronts the subject with their own unconscious, repressed impulses. Expanding on the idea, psychoanalytic theorist Jacques Lacan wrote that the uncanny places us "in the field where we do not know how to distinguish bad and good, pleasure from displeasure," resulting in an irreducible anxiety gesturing to the Real. The concept has since been taken up by a variety of subsequent thinkers and theorists.
Philosopher F.W.J. Schelling raised the question of the uncanny in his late Philosophie der Mythologie of 1835, postulating that the Homeric clarity was built upon a prior repression of the uncanny.
In The Will to Power manuscript, German philosopher Friedrich Nietzsche refers to nihilism as "the uncanniest of all guests" and, earlier, in On the Genealogy of Morals he claims it is the "will to truth" that has destroyed the metaphysics that underpins the values of Western culture. Hence, he coins the phrase "European nihilism" to describe the condition that afflicts those Enlightenment ideals that seemingly hold strong values yet undermine themselves.
Uncanniness was first explored psychologically by Ernst Jentsch in a 1906 essay, On the Psychology of the Uncanny. Jentsch defines the Uncanny as: being a product of "...intellectual uncertainty; so that the uncanny would always, as it were, be something one does not know one’s way about in. The better oriented in his environment a person is, the less readily will he get the impression of something uncanny in regard to the objects and events in it." He expands upon its use in fiction: