If nature has made any
one thing less susceptible than all others of exclusive property, it
is the action of the thinking power called an idea, which an
individual may exclusively possess as long as he keeps it to himself;
but the moment it is divulged, it forces itself into the possession of
every one, and the receiver cannot dispossess himself of it. Its
peculiar character, too, is that no one possesses the less, because
every other possesses the whole of it. He who receives an idea from
me, receives instruction himself without lessening mine; as he who
lights his taper at mine, receives light without darkening me. That
ideas should freely spread from one to another over the globe, for the
moral and mutual instruction of man, and improvement of his condition,
seems to have been peculiarly and benevolently designed by nature,
when she made them, like fire, expansible over all space, without
lessening their density in any point, and like the air in which we
breathe, move, and have our physical being, incapable of confinement
or exclusive appropriation.
-- Thomas Jefferson
in a letter to Mr. Isaac McPherson, Monticello August 13, 1813,
reproduced in Writings Of Thomas Jefferson: Being His Autobiography
Correspondence Reports Messages Addresses And Other Writings Official And
Private Published By The Order Of The Joint Committee Of Congress On
The Library From The Original Manuscripts Deposited In The Department Of
State, With Explanatory Notes Tables Of Contents And A Copious Index To
Each Volume As Well As A General Index To The Whole By The Editor
H.A. Washington. Vol VI. Published By Taylor & Maury Washington D.C.
1854. p 180-181