Public (AmE: /ˈpəblɪk/; BrE: /ˈpʌblɪk/) is an important, but controversial, term widely used in political, social and legal theory, research and citizenship, with many different nuances and subtleties of meaning, most of which are in some way related to notions of openness, generality and connecting independent parts with a larger whole. The term is used regularly by political scientists and philosophers, politicians, journalists, policy analysts, economists, lawyers and members of the general public.
It is ordinarily used as an adjective to characterize things which are shared by, open or available to everyone, well or generally known, universally available or without limit, done or made on behalf of the community as a whole, open to general or unlimited viewing or disclosure, frequented by large numbers of people or for general use, a place generally open or visible to all pertaining to official matters or maintained at taxpayer expense. (A list of more than 50 instances of such terms is included on the Related Articles page of this entry, and brief discussions of several of the most important terms are discussed briefly below.)
Public can also be used as a noun to refer to an undifferentiated group of people, often sharing some interest in common. For example, the public might be everyone or all citizens of a nation-state (two uses of the general public), members of a particular community, state, dominion, district, precinct or other political jurisdiction (e.g., the citizens of Canada are the Canadian public), those who share a particular interest or activity (those who watch television are called the viewing public), fans or followers or an audience, particularly of a widely-known figure (E.g., "Cher came out to greet her public").
Public can also be used in other ways. To go public, for example, can mean to offer for open or general sale something (e.g. a stock offering) that was previously held or sold privately, or to publish, print, broadcast or distribute news or information, or disclose previously private, confidential, secret or concealed information. Publicize also has many different uses which come down to the idea of making, transforming or converting something from private to public.
The modern [English term] is derived from the Middle English (14th century) publique, which in turn comes from Anglo-French, and ultimately from the Latin publicus; akin to Latin populus, or people.
Using published instances, the Online Etymological Dictionary traces the connotation "pertaining to the people," from 1436 and the connotation "open to all in the community" from 1542 and reference to "the community" from 1611. The same source also lists a number of later connotations. As noted in the section on res publica below, statecraft in the medieval and early modern period frequently rejected such ancient and contemporary connotations in their use of the term.
Res publica is a Latin term, originating in ancient Roman politics and law, and meaning, literally "public thing" or "public matter". Many modern sources take that to correspond closely to the meaning of contemporary phrases like "public issue" or "public concern". While the original Latin phrase itself has drawn attention from a wide variety of political philosophers, the term is of greatest and most far-reaching importance as the root of the term republic.
Richard Sennett, in The Fall of Public Man suggests a range of concerns somewhat akin to the social bonds of civil society:
- A res publica stands in general for those bonds of association and mutual commitment which exist between people who are not joined together by ties of family or intimate association; it is the bond of a crowd, of a 'people', of a polity, rather than the bonds of family or friends. 
Although the term public has been in widespread use for a long time, there has been at least one major transformation in its meaning in the specific context of government that appears to be related to the emergence of modern democracy (“government of the people, by the people and for the people.”). In several seventeenth and eighteenth century European monarchies under the influence of absolutism and the idea that the political authority of a sovereign ruler was derived directly from God, many statements were made that sound paradoxical to contemporary ears but made perfect sense at the time: Statements like “This is a public matter. The people have no right to express their views on the issue, or even to know about it.” Public interest, in other words, referred to the interests of the state, but for autocracies, strong monarchies, oligarchies and other non-democratic political states, public interest (as state interest) was not equated with the interest, knowledge or awareness of the people.
Publicity is a term which has also experienced a major transformation. Originally meaning (and still occasionally used in the sense of) something like the inherent quality of "publicness" attributed to someone or something, publicity is now much more commonly used to describe the process of or procedures for making something known to the public, particularly when it is done by an organization, committee or public relations agency or professional. Thus, when one hears, for example, of "the publicity of legislative acts" the phrase is much more likely to refer to actions or activities publicizing those acts than to the inherent qualities of actions by a group of persons functioning as a legislative body.
The term general public has come into wider usage since the early twentieth century to differentiate "all of us", or "all citizens" constituted as a public from a wide variety of possible special publics. The possibility of multiple publics (and its logical corollary of multiple - and possibly conflicting - public interests) was first posed by the philosopher John Dewey, who tied it to shifting understandings of political interest and awareness.
Dewey and Lippmann on Publics
In Public Opinion (1922) Walter Lippmann offered his fullest statement of the role of newspapers in modern representative democracy, the public and a passive, information-processing view of public opinion formation. Lippmann argued that modern industrial democracies were too complex for average citizens to effectively understand and direct. Government must be largely carried out by an expert-based governing class. He saw the accuracy of news and the protection of journalistic sources as principal problems of democracy and presented the general public as a bewildered and rather passive herd. In modern, industrial society, according to Lippmann, it was the job of the journalist to translate the actions and motives of the governing class of bureaucratic experts and specialists into terms that the general public could comprehend. He found the notion of actual government by the people (as opposed to their better-informed representatives) altogether implausible.
Three years later, in The Phantom Public (1925), Lippman's view reached what proved to be its outer limit when Lippmann recognized that experts could themselves be outsiders to a problem outside their rather narrow domains of expertise. Apart from the few who understood any particular issue, even other experts were not possessed of sufficient accurate information to be capable of effective action. Lippmann may have been influenced in this view, some authorities believe, by the views of European Fascists who were already in power in Italy and gaining strength elsewhere in Europe at the time or by advocates of technocracy.) Lippmann’s view is that public affairs are largely the responsibility of elected representatives and appointed officials who are expert elites. Many other progressives expressed similar views, including Woodrow Wilson, Herbert Croly and Mary Parker Follett's early (1896) study of the U.S. House of Representatives. Cite error: Invalid
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Two years later, in The Public and its Problems,  John Dewey, who was the best-known American philosopher and public intellectual of the first half of the twentieth century, offered a response to Lippmann’s case for representative democracy.Dewey argued that politics is the responsibility of all citizens, and that adequate education would provide citizens with the knowledge needed to be involved in politics. In the Dewey model, there was a place for ordinary citizens alongside elites and experts in government, and journalism assumed an educational role. Dewey also worked out the implications of expertise for the public as well as leaders: In reply to Lippman's implied (and debilitating) division of labor among experts, he posited multiple publics with specialized and focused interests paralleling those of the experts. Decades later, the political scientist and theorist Robert Dahl in a study of New Haven politics detailed similar public dynamics between experts, elites and interested publics and numerous other political studies have detailed focused publics as "constituencies" of public bureaucracies. At about the same time David Easton and other political systems theorists theorized feedback loops ( notably "public opinion") back to the experts and leaders, and Lazarsfeld and Katz identified a "two-step flow" of communication in which public opinion formation was mediated by an even more complex division of labor involving not only experts and publics but also "opinion leaders" whose greater expertise and knowledge is recognized by other members of the public who take their cues from these opinion-makers.
C. Wright Mills & Mass vs. Public
In the Power Elite (1956) C. Wright Mills distinguished between "masses" and "publics" in the following manner:
- "In a public, as we may understand the term,
- (1) Virtually as many people express opinions as receive them,
- (2) Public communications are so organised that there is a chance immediately and effectively to answer back any opinion expressed in public.
- (3) Opinion formed by such discussion readily finds an outlet in effective action, even against – if necessary – the prevailing system of authority.
- And (4) authoritative institutions do not penetrate the public, which is thus more or less autonomous in its operations.
- In a mass,
- (1) Far fewer people express opinions than receive them; for the community of publics becomes an abstract collection of individuals who receive impressions from the mass media.
- (2) The communications that prevail are so organised that it is difficult or impossible for the individual to answer back immediately or with any effect.
- (3) The realisation of opinion in action is controlled by authorities who organise and control the channels of such action.
- (4) The mass has no autonomy from institutions; on the contrary, agents of authorised institutions penetrate this mass, reducing any autonomy it may have in the formation of opinion by discussion".
- "In a public, as we may understand the term,
The term public domain is a legal concept referring to the full set of public concerns or res publica. This may include public property, information and knowledge not subject to copyright or patent and a wide range of other public matters. News is a particularly tricky aspect of the public domain, in large part, because what is news is defined largely by private, proprietary institutions (newspapers, news magazines, and broadcast news) under circumstances that allow them to retain limited and formal copyrights. Thus, the outcome of an election, for example, is generally in the public domain, both in terms of who won and the vote totals. Particular news stories reporting those outcomes, however, may be only partly in the public domain.
The Internet and the public domain
One of the principal reasons for controversy over the nature of the public domain in the past two decades has been the evolution of the internet.
The term public good is also used in several different senses. For economists, public good is a technical term for goods (commodities and services that possess two defining characteristics: non-exclusion and non-rivalry. In general political usage, the term is used in a less technical, more normative, sense to characterize positive or desired outcomes of public or governmental action.
Public journalism may refer to citizen journalism, or reporting and news commentary carried out by ordinary citizen-journalists or to civic journalism which is a type of politically engaged journalism conducted by certain news organizations. Public journalism ordinarily originates in critique; specifically in criticism or outright rejection of the notion of the journalist as neutral observer of public events, political and social processes. It represents a Lippmannesque conception of journalism as exercising a uniquely important influence on the direction of public affairs.
In The Roots of Civic Journalism, David K. Perry  characterized the practitioners of civic journalism in terms of five shared beliefs:
- Situating news media and journalists as active participants in civic life, rather than as detached observers.
- Viewing newspapers as fora for discussion of community issues.
- A preference for issues, events and problems important to ordinary people.
- Viewing public opinion as one product of the process of public deliberation by members of a community.
- Strategic use of journalism to enhance social capital.
Many observers would also extend the same beliefs to practitioners of citizen journalism, which tends to be somewhat less self-aware of its philosophical and theoretical basis.
Public opinion is an important concept in democratic theory, and has become an essential concept in mass communication studies as well.
An important contribution to the process of public opinion formation was the Lazarsfeld-Katz "two-step flow of communication" model and the related concept of opinion leaders.  Opinion leaders, in this model, are the most active and best informed media consumers, who come to be respected for their expertise by others in their daily lives, and consequently through processes of social influence have an unusually strong influence on public opinion, representing not only their own opinions but also others whose opinions they influence. Opinion leadership often tends to be subject-specific, with physicians having an inordinate influence on issues of medicine and health, engineers on technical questions, clergy on religious matters and so on. The concept of champions has sometimes been used to translate the behavioral insights of the two-step flow model into the context of policy formation as part of the policy process in organizations.
Public sector, sometimes also referred to as the state sector, is easiest to understand in contrast with its opposite, the private sector and its close kinship in modern democracies with the public sphere. The term public sector is ordinarily applied to the organizations and institutions of government (as distinct from the public sphere - see below - which ordinarily applies to much more than just government). In this sense, private sector would ordinarily equate with most uses of nongovernmental sector, and include not only all forms of private behavior, including intimate, confidential, and secret conduct, but also entities and activities operating in market, or "for-profit" modes as well as private (i.e., nongovernmental) nonprofits (Thus, for example, public nudity, for example, walking down a city street without clothes on, would ordinarily be considered to occur in the public sphere, but not necessarily in the public sector, while confidential discussions of public nudity as a legal issue between two elected officials might be viewed in exactly opposite terms: behavior taking place in the public sector but not in the public sphere. One possible explanation or justification for sunshine laws, open meeting acts and assorted other similar regulations and legislative acts would be as actions in the public interest to coordinate public sector and public sphere more closely.
At the national level in the United States, the public sector involves millions of public employees and office holders and many thousands of organizations. At the federal level this would include the Executive Branch, headed by the President, both houses of Congress (Senate and the House of Representatives) and the federal Judiciary, of which the 9-member Supreme Court sits at the apex, but which also includes all federal judges and the Circuit Courts of Appeals. The federal-level public sector also normally includes all of the thousands of civilian and military federal organizations.
The entire public sector would also include all branches of government at the state and local levels as well as a number of regional entities like the Tennessee Valley Authority, federal state partnerships like the Appalachian Regional Commission and assorted regional councils of government like the Minneapolis-St.Paul regional Metropolitan Council.
In the idea of a public sector we find one of the places where the multiple contemporary meanings of the term public come into play. Public company is the name used for any company whose stock is publicly traded on a stock exchange like the New York Stock Exchange, even though such companies are privately owned. (Note: Public-private distinctions can all get very confusing and even inconsistent: Private in this case also has its own many connotations. Private ownership of publicly traded companies, for example, does not refer to ownership by low-level military personnel, nor to covert or confidential activities, but solely to the characteristics of ownership and trading, respectively. Both of these are not altogether consistent with the meaning of the terms public and private sectors.)
The role and scope of the public sector has been the subject of ongoing differences between, among others, liberals, conservatives, socialists, libertarians, fascists and others in the public sphere at least since the late eighteenth century.
The phrase public sphere has come into widespread use in recent decades in the context of the rediscovery of civil society to describe or characterize open or unconstrained social and political spaces, particularly those for purposes of assembly and public deliberation. In a broader sense, the public sphere also extends to a much broader range of phenomena also including public sidewalks, public lands and the full range of public resources, services facilities.
The structural transformations
Jürgen Habermas traced what he identified as two subsequent "structural transformations" of the public sphere and related changes in social and political structure in a book entitled The Structural Transformation of the Public Sphere.  This work was first published in German in 1962 as Strukturwandel der Öffentlichkeit  but not published in English translation until 1989.
Habermas argued that an unprecedented "bourgeois public sphere" emerged in certain European cities (in particular, London, Paris and Berlin) in the late 18th century centered on newspapers and periodicals and assemblies like the salons found in all three cities, coffeehouses of London, cafes of Paris and tischgesellschaften ("table societies") of Berlin. This emergence, he argued, came about in response to the new prospects for democracy and republican politics arising from the Enlightenment and the American and French Revolutions. This was followed late in the late 19th century by a second transformation characterized by the decline and dissolution of this bourgeois public sphere under the forces of bureaucratic industrial society in which corporate media and political elites came to define and dominate the public sphere.
- Richard Sennett. The Fall of Public Man. New York: Alfred A. Knopf. 1976. p. 3-4 ISBN 039448715X
- John Dewey. The Public and Its Problems. New York: Holt. 1927
- Robert A. Dahl. Who Governs? Democracy and Power in an American City. New Haven: Yale University Press. 1961.
- David K. Perry, Roots of Civic Journalism: Darwin, Dewey, and Mead. Lanham, MD: Rowman and Littlefield, 2003. ISBN: 0761826343
- Katz, E., & Lazarsfeld, P. F. (1955). Personal influence: The part played by people in the flow of mass communication. Glencoe, IL: Free Press.
- Habermas, J. (1989). The structural transformation of the public sphere : an inquiry into a category of bourgeois society. Cambridge, Mass.: MIT Press. ISBN 0262581086
- Strukturwandel der Öffentlichkeit. Untersuchungen zu einer Kategorie der bürgerlichen Gesellschaft (Habil.), Neuwied 1962