Art criticism is the discussion or evaluation of visual art. Art critics usually criticise art in the context of aesthetics or the theory of beauty. A goal of art criticism is the pursuit of a rational basis for art appreciation but it is questionable whether such criticism can transcend prevailing socio-political circumstances. The variety of artistic movements has resulted in a division of art criticism into different disciplines which may each use different criteria for their judgements. The most common division in the field of criticism is between historical criticism and evaluation, a form of art history, and contemporary criticism of work by living artists. Despite perceptions that art criticism is a much lower risk activity than making art, opinions of current art are always liable to drastic corrections with the passage of time. Critics of the past are often ridiculed for either favouring artists now derided (like the academic painters of the late 19th century) or dismissing artists now venerated (like the early work of the Impressionists). Some art movements themselves were named disparagingly by critics, with the name later adopted as a sort of badge of honour by the artists of the style (e.g., Impressionism, Cubism), with the original negative meaning forgotten. Artists have often had an uneasy relationship with their critics. Artists usually need positive opinions from critics for their work to be viewed and purchased; unfortunately for the artists, only later generations may understand it. Art is an important part of being human and can be found through all aspects of our lives, regardless of the culture or times. There are many different variables that determine one's judgment of art such as aesthetics, cognition or perception. Art can be objective or subjective based on personal preference toward aesthetics and form. It can be based on the elements and principle of design and by social and cultural acceptance. Art is a basic human instinct with a diverse range of form and expression. Art can stand-alone with an instantaneous judgment or can be viewed with a deeper more educated knowledge. Aesthetic, pragmatic, expressive, formalist, relativist, processional, imitation, ritual, cognition, mimetic and postmodern theories are some of many theories to criticize and appreciate art. Art criticism and appreciation can be subjective based on personal preference toward aesthetics and form, or it can be based on the elements and principle of design and by social and cultural acceptance. Art criticism has many and often numerous subjective viewpoints which are nearly as varied as there are people practising it. It is difficult to come by a more stable definition than the activity being related to the discussion and interpretation of art and its value. Depending on who is writing on the subject, 'art criticism' itself may be obviated as a direct goal or it may include art history within its framework. Regardless of definitional problems, art criticism can refer to the history of the craft in its essays and art history itself may use critical methods implicitly. According to art historian R. Siva Kumar, 'The borders between art history and art criticism... are no more as firmly drawn as they once used to be. It perhaps began with art historians taking interest in modern art.' Art criticism includes a descriptive aspect, where the work of art is sufficiently translated into words so as to allow a case to be made. The evaluation of a work of art that follows the description (or is interspersed with it) depends as much on the artist's output as on the experience of the critic. There is in an activity with such a marked subjective component a variety of ways in which it can be pursued. As extremes in a possible spectrum, while some favour simply remarking on the immediate impressions caused by an artistic object, others prefer a more systematic approach calling on technical knowledge, favoured aesthetic theory and the known sociocultural context the artist is immersed in to discern their intent. Critiques of art likely originated with the origins of art itself, as evidenced by texts found in the works of Plato, Vitruvius or Augustine of Hippo among others, that contain early forms of art criticism. Also, wealthy patrons have employed, at least since the start of Renaissance, intermediary art-evaluators to assist them in the procurement of commissions and/or finished pieces.