
“There are things known
and there are things unknown
and in between are the doors.”
Aldous Huxley, using the term "the doors of perception" which originated with William Blake in The Marriage of Heaven and Hell. It is sometimes credited to Morrison because he cited it in interviews as the inspiration for the name The Doors and without always crediting Huxley as the source.
Misattributed
Variant: There are things known and there are things unknown, and in between are the doors of perception.
Source: Letters from Joe