Conceptual art, sometimes simply called Conceptualism, is art in which the concept(s) or idea(s) involved in the work take precedence over traditional aesthetic and material concerns. Many works of conceptual art, sometimes called installations, may be constructed by anyone simply by following a set of written instructions. This method was fundamental to American artist Sol LeWitt's definition of Conceptual art, one of the first to appear in print:
In conceptual art the idea or concept is the most important aspect of the work. When an artist uses a conceptual form of art, it means that all of the planning and decisions are made beforehand and the execution is a perfunctory affair. The idea becomes a machine that makes the art.
Tony Godfrey, author of Conceptual Art (Art & Ideas) (1998), asserts that conceptual art questions the nature of art, a notion that Joseph Kosuth
elevated to a definition of art itself in his seminal, early manifesto of conceptual art, "Art after Philosophy" (1969). The notion that art should examine its own nature was already a potent aspect of the influential art critic Clement Greenberg's vision of Modern art during the 1950s. With the emergence of an exclusively language-based art in the 1960s, however, conceptual artists such as Joseph Kosuth, Lawrence Weiner and the English Art & Language group began a far more radical interrogation of art than was previously possible (see below). One of the first and most important things they questioned was the common assumption that the role of the artist was to create special kinds of material objects.
Through its association with the Young British Artists and the Turner Prize during the 1990s, in popular usage, particularly in the UK, "conceptual art" came to denote all contemporary art that does not practice the traditional skills of painting and sculpture. It could be said that one of the reasons why the term "conceptual art" has come to be associated with various contemporary practices far removed from its original aims and forms lies in the problem of defining the term itself. As the artist Mel Bochner suggested as early as 1970, in explaining why he does not like the epithet "conceptual", it is not always entirely clear what "concept" refers to, and it runs the risk of being confused with "intention." Thus, in describing or defining a work of art as conceptual it is important not to confuse what is referred to as "conceptual" with an artist's "intention."