Invisible Pink Unicorn

The Invisible Pink Unicorn (IPU) is the goddess of a parody religion used to satirize theistic beliefs, taking the form of a unicorn that is paradoxically both invisible and pink. She is a rhetorical illustration used by atheists and other religious skeptics as a contemporary version of Russell's teapot, sometimes mentioned in conjunction with the Flying Spaghetti Monster.

The IPU is used to argue that supernatural beliefs are arbitrary by, for example, replacing the word God in any theistic statement with Invisible Pink Unicorn. The mutually exclusive attributes of pinkness and invisibility, coupled with the inability to disprove the IPU's existence, satirize properties that some theists attribute to a theistic deity.

Russell's teapot is an analogy first coined by the philosopher Bertrand Russell (1872–1970) to illustrate that the philosophic burden of proof lies upon a person making scientifically unfalsifiable claims rather than shifting the burden of proof to others, specifically in the case of religion. Russell wrote that, if he claims that a teapot orbits the Sun somewhere in space between the Earth and Mars, it is nonsensical for him to expect others to believe him on the ground that they cannot prove him wrong. Russell's teapot is still referred to in discussions concerning the existence of God.

The IPU seems to have become notable primarily through online culture: in addition to alt.atheism, where IPU still frequently comes up in discussions, there are now a number of web sites dedicated to Her. The earliest documented reference to the IPU was on July 7, 1990, on the Usenet discussion group alt.atheism. Other sources concerning IPU state that she was "revealed to us" on alt.atheism.

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