Uncanny

The psychological concept of the uncanny as something that is strangely familiar, rather than just mysterious, was perhaps first fixed by Sigmund Freud in his essay Das Unheimliche.

Because the uncanny is familiar, yet incongruous, it has been seen as creating cognitive dissonance within the experiencing subject, due to the paradoxical nature of being simultaneously attracted to yet repulsed by an object. This cognitive dissonance often leads to an outright rejection of the object, as one would rather reject than rationalize, as in the uncanny valley effect.

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 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:

In telling a story one of the most successful devices for easily creating uncanny effects is to leave the reader in uncertainty whether a particular figure in the story is a human being or an automaton and to do it in such a way that his attention is not focused directly upon his uncertainty, so that he may not be led to go into the matter and clear it up immediately.

...
Wikipedia