| Tell me about|
|For our next session...|
|Popping into your mind|
|—Robert M. Pirsig|
Systematically shared beliefs between close social groups, such as religious systems, are commonly regarded as delusions amongst scientists, philosophers and psychologists, but are typically considered exempt by most clinical diagnostic criteria (e.g., the Diagnostic and Statistical Manual of Mental Disorders). The noted New Atheist, Richard Dawkins, wrote a book entitled The God Delusion, in which he asserted that the question of God's existence was tied to the question of special creation, and then argued that since special creation has largely been demonstrated to be false, belief in God is a delusion.
Sometimes a correct belief may be mistaken for a delusion, such as when the belief in question is not demonstrably false but is nevertheless considered beyond the realm of possibility. A specific variant of this is when a person is fed lies in an attempt to convince them that they are delusional, a process called "gaslighting," after the 1938 play Gaslight, the plot of which centered around the process.
 See also
- See the Wikipedia article on Gas Light (the play).
- See the Wikipedia article on Gaslight (1940 film).
- See the Wikipedia article on Gaslight (1944 film).