For numerous reasons, the most difficult word to define without starting endless argument! Many definitions have been proposed. At least art involves a degree of human involvement-- through manual skills or thought-- as with the word "artificial," meaning made by humans instead of by nature. Definitions vary in how they divide all that is artificial into what is and isn't art. The most common means is to rely upon the estimations of art experts and institutions.

Artists, museumcurators, art patrons, art educators, art critics, art historians, and others involved with art change their ideas about it over time. Early in the twentieth century, for instance, artists expanded the definition of art to include such things as abstraction, collage, and ready-mades. Even in the second half of the twentieth century, the art world expanded its definition of art to include textiles, costumes, jewellery, photography, video, concepts, and performances as art. Only in the last ten or twenty years works of various native peoples have come to be considered art rather than artefacts.

However, people of some cultures do not (or refuse to) refer to some works as "art." Because of this, many people have taken to using the broader terms material culture or visual culture when referring to such works. No American Indian language includes such a word as art. The Japanese created such a word only after coming into contact with European ideas.

• "Life is short, art endures..." Hippocrates (c. 460 - 400 B.C.) Greek philosopher. Aphorisms, Section I, 1.
• "Art completes what nature cannot bring to finish" Aristotle (384 - 322 B.C.), Greek philosopher.
• "Art is a half-effaced recollection of a higher state from which we have fallen since the time of Eden."
  Saint Hildegarde (1098-1179).
• "That which is static and repetitive is boring. That which is dynamic and random is confusing. In between lies art."
  John A. Locke (1632-1704), English philosopher.
• "Criticism is easy, art is difficult." Detouches [Philippe Nericault] (1680-1754) French. Le Glorieux, 1732.
• "Were I called on to define, very briefly, the term Art, I should call it 'the reproduction of what the Senses perceive in Nature through the veil of the soul.' The mere imitation, however accurate, of what is in Nature, entitles no man to the sacred name of 'Artist.' Edgar Allan Poe (1809-1845), U.S. poet, critic, short-story writer. "Marginalia," in Southern Literary Messenger (Richmond, VA, June 1849; reprinted in Essays and Reviews, 1984).
• "Shall I tell you what I think are the two qualities of a work of art? First, it must be the indescribable, and second, it must be inimitable." Pierre Auguste Renoir (1841-1914), French Impressionist. From an interview with Walter Pach in Scribner's Magazine, May, 1912.
• "You come to nature with all her theories, and she knocks them all flat." Pierre Auguste Renoir.
• "It is art that makes life, makes interest, makes importance... and I know of no substitute whatever for the force and beauty of its process." Henry James (1843-1916), U.S. author. Letter, July 10, 1915
• "Art requires philosophy, just as philosophy requires art. Otherwise, what would become of beauty?"
  Paul Gauguin (1848-1903), French Post-Impressionist. Intimate Journals (translated by Van Wyck Brooks, 1923; reprinted 1930, p. 193).
• "It is through art, and through art only, that we can realize our perfection; through art and art only that we can shield ourselves from the sordid perils of actual existence." Oscar Wilde (1854-1900), English poet and playwright. The Critic as Artist, part II, 1891.
• "Art is the most intense mode of invidualism that the world has known." Oscar Wilde.
• "Paradoxically though it may seem, it is none the less true that life imitates art far more than art imitates life."
  Oscar Wilde.
• "Art is the imposing of a pattern on experience, and our aesthetic enjoyment is recognition of the pattern."
  Alfred North Whitehead (1861-1947), British philosopher. Dialogues, June 10, 1943 (1954).
• "Only through art can we get outside of ourselves and know another's view of the universe which is not the same as ours and see landscapes which would otherwise have remained unknown to us like the landscapes of the moon. Thanks to art, instead of seeing a single world, our own, we see it multiply until we have before us as many worlds as there are original artists.... And many centuries after their core, whether we call it Rembrandt or Vermeer, is extinguished, they continue to send us their special rays." Marcel Proust (1871-1922) French writer. The Maxims of Marcel Proust, translated by Justin O'Brien, published 1948.
• "Surely all art is the result of one's having been in danger, of having gone through an experience all the way to the end, where no one can go any further." Rainer Maria Rilke (1875-1926), German poet. Letter, June 24, 1907, to his wife (published in Rilke's Letters on Cézanne, 1952; translated 1985).
• "True art is characterized by an irresistible urge in the creative artist." Albert Einstein (1879-1955), German mathematician and physicist.
• "Art does not reproduce the visible; rather, it makes visible." Paul Klee (1879-1940), Swiss artist. See Bauhaus.
• "Art washes away from the soul the dust of everyday life." Pablo Picasso (1881-1973), Spanish artist.
• "For Arp, art is Arp." Marcel Duchamp (1887-1968), French-American Cubist, then Dadaist, writing about Jean [aka Hans] Arp (French, 1887-1966), another Dadaist / Surrealist. From a catalogue, Arp, Galleria Schwarz, Milan, 1965.
• "Art is the unceasing effort to compete with the beauty of flowers -- and never succeeding." Marc Chagall (1889-1985), French Surrealist painter.
• "But all categories of art, idealistic or realistic, surrealistic or constructivist (a new form of idealism) must satisfy a simple test (or they are in no sense works of art): they must persist as objects of contemplation."
  Herbert Read (1893-1968), British art writer. Modern Sculpture.
• "Art is the objectification of feeling, and the subjectification of nature." Susanne Langer (1895-1985). Mind, An Essay on Human Feeling.
• "Art is an adventure into an unknown world, which can only be explored by those willing to take the risks."
  Mark Rothko (1903-1970), American Abstract Expressionist painter.
• "Art is coming face to face with yourself. That's what's wrong with Benton. He came face to face with Michelangelo-- and he lost." Jackson Pollock (1912-1956), American Abstract Expressionist painter, about Thomas Hart Benton (American, 1889-1975), painter. See American Scene painting, social realism, and mural.
• "I have the loftiest idea, and the most passionate one, of art. Much too lofty to agree to subject it too anything. Much too passionate to want to divorce it from anything." Albert Camus (1913-1961), French existentialist writer. Notebooks, 1942-1951.
• "Art establishes the basic human truths which must serve as the touchstone of our judgment." John F. Kennedy (1917-1963) U.S. president. An address at Amherst College, October 26, 1963.
• "I am for an art that takes its forms from the lines of life itself, that twists and extends and accumulates and spits and drips and is heavy and coarse and blunt and sweet and stupid as life itself." Claes Oldenburg (1929-), American Pop artist. In an exhibition catalogue, 1961.
• "Art today is a new kind of instrument, an instrument for modifying consciousness and organizing new modes of sensibility . . .  Artists have had to become self-conscious aestheticians: continually challenging their means, their materials and methods." Susan Sontag (1933-), American writer. Against Interpretation.
• "My dear Tristan, to be an artist at all is like living in Switzerland during a world war." Tom Stoppard (1937-), American [?] playwright. Travesties, 1974.
• "Art is making something out of nothing and selling it." Frank Zappa (1940-1993), American musical satirist.
• "Do not imagine that Art is something which is designed to give gentle uplift and self-confidence. Art is not a brassiere. At least, not in the English sense. But do not forget that brassiere is the French word for life-jacket."
  Julian Barnes (1946-), English writer. Flaubert's Parrot.