Traditionally, the public domain has been defined as the set of intellectual works that can be copied, used and reused without restriction of any kind. For the purposes of this essay I wish to widen this a little and make the public domain synonymous with ‘open’ knowledge, that is, all ideas and information that can be freely used, redistributed and reused. The word ‘freely’ must be loosely interpreted – for example the requirement of attribution or even that derivative works be re-shared, does not render a work unfree.

This public domain is very large. It includes the contents of the traditional public domain such as works originally subject to monopoly protection but where the protection has expired, for example Shakespeare’s plays, which were once subject to copyright, as well as items never subject to protection, for example the theory of relativity. It also includes open source software and work released under (some) Creative Commons licenses. As such, it consists of almost all of humanity’s intellectual output up until the very recent present (for patented ideas it excludes approximately the last 20 years and for copyrighted works
approximately the last 100 years).

... Our current paradigm
represents a form of monomania in which monopoly rights, in the form of intellectual property, displace all else from our thinking on this subject. It binds us to a narrow, and erroneous, viewpoint in which innovation is central but access is peripheral. The system it has engendered is now so distorted that its
social and commercial costs in several key areas have become large. It is therefore high time to restore balance, in particular by taking proper account of the public domain and open approaches to knowledge production. It is only by doing so that we will be able to take full advantage of the possibilities offered by this digital age.