Perhaps the best way to define social responsibility in librarianship is by first defining intellectual freedom.
Intellectual freedom is currently librarianship's 'core value'.
Beginning in 1939 ALA began to document intellectual freedom and oppose censorship. They must serve all members of the community. Libraries should provide access to all kinds of information and challenge censorship in all its forms. This is achieved by taking a detached and neutral perspective in all professional duties. Personal persuasions and interests should be set aside in the pursuit of intellectual freedom.