From: rms@gnu.ai.mit.edu (Richard Stallman)
Subject: Copyleft vs Public Domain
Organization: GNUs Not Usenet
Distribution: gnu
Date: Fri, 8 Jan 1993 22:13:37 GMT

 		    Copyleft vs Public Domain

Some people ask why the FSF uses copyleft (the General Public License
or GPL) to specify conditions for copying GNU software.  Why not just
put the software in the public domain?

The purpose of the GNU project is to give users in general the freedom
to use software in many ways.  We want them to be free to study and
change programs, and to cooperate with each other by sharing
programs.  This is what we mean by "free software".  The GPL achieves
this better than the public domain, because (1) it prevents the
freedom from being stripped off when the program is distributed, and
(2) it takes away the incentive to be uncooperative by refusing to
share an improvement.

Copyleft does prevent certain people from doing what they would like
to do.  Those who would like to take GNU software, make some changes,
and call the result their property are not free to do so.  We think
this is a good thing.

To understand why, first note that it is not possible for society to
permit "all possible freedom," because some freedoms are incompatible
with others.  This is often stated as, "Your freedom to swing your
fist ends where my face begins."

We always resolve the conflicts between freedoms by prioritizing
them.  For example, the quotation above implicitly assumes that the
freedom not to be punched is more important than the freedom to swing
a fist.

There is more than one way to apply a concept such as "free" to the
area of software, because there are different choices of priority.
The question is not, which is the true meaning of "free software", but
rather, which of the valid meanings is best.

The GNU project is based on the idea that the freedom to decide your
own actions with the programs you use--for example, whether to copy
them or change them--is more important than occasional power over
other people's actions.

Making a program proprietary means interfering with the important
freedoms--other people's freedom to study, share and change the
program.  This is the software analogue of swinging the fist through a
user's face.  Preventing this may bother those who want to swing the
fist.  But don't sympathize too much; you might be one of the users
who would get it in the face.

If not for the GPL, most users of our software would not have the
freedom to redistribute and change it.  That is not just speculation;
the examples of X Windows, TeX, and Berkeley's Unix extensions show
that most users of these programs have only proprietary versions and
do not have the freedom to share or change them.  The first authors of
these programs did not themselves take away those freedoms, but did
not defend them either.  Where that path leads was clear when the GNU
project was started, and therefore we chose another path.

The GPL also encourages companies which make improved versions to
return their improvements for inclusion in the standard version.  If
not for this, GCC and Emacs would not be nearly as good as they are.

But is this enough justification?  That is a fundamental philosophical
question.  Some people believe it wrong to place any restrictions on
anyone, ever--even restrictions against making any other
restrictions.  Those readers who believe in pacifism and condemn use
of force even to protect innocent victims would naturally disagree
with our approach.

That is not the philosophy of the GNU project, however.  We are not
pacifists, and being passive and never saying "No" to anyone is not
our goal.  Our aim is positive--to give the users the freedom to
cooperate, which is distinguished from the freedom to obstruct.  That
has been the goal ever since the beginning.

If we put our software in the public domain, then we would have a
great excuse to make.  We could say, "Don't blame us if you have no
freedom to share and change this program--it was that other guy who
redistributed it with a nondisclosure license and no source."  But we
want to succeed in giving users that freedom, not prepare excuses for
failure.  We use the GPL because it succeeds.
Xref: sparky gnu.misc.discuss:4349 talk.philosophy.misc:3244 misc.legal:22291