Artists who have produced experimental innovations have been motivated by aesthetic criteria: they have aimed at presenting visual perceptions. Their goals are imprecise, so their procedure is tentative and incremental.

Artists have made innovations in many areas... But whatever the nature of an artist's innovation, its importance ultimately depends on the extent of its influence on other artists.

Titian and Rembrandt, Monet and Rodin, Frank Lloyd Wright and Le Corbusier, Mark Twain and Henry James, Robert Frost and Elizabeth Bishop, to name a few. Twain wrote 'Tom Sawyer' at 41 and bettered it with 'Huckleberry Finn' at 50; Wright completed Fallingwater at 72 and worked on the Guggenheim Museum until his death at 91.

Artists who have produced experimental innovations have been motivated by aesthetic criteria: they have aimed at presenting visual perceptions. Their goals are imprecise, so their procedure is tentative and incremental.

The precision of their goals allows conceptual artists to be satisfied that they have produced one or more works that achieve a particular purpose... a problem solved can free him to pursue new goals.

Important artists are innovators whose work changes the practices of their successors.

There are two very different types of artists: those I call Old Masters, who work by trial and error and tend to improve with age, and conceptual people, or Young Geniuses, who generally do their best work early in their careers.