Slow execution was typically associated with lasting artistic value in classical art theory. Thus Zeuxis explained that he painted "slowly so that my paintings will live for a long time," and Apelles mocked the artist who completed a painting in a single day saying, "you need not tell me … the work itself shows it." In the Renaissance too mistrust of rapid execution remained paramount. For example, Vasari himself was strongly criticized for completing his frescoes in the Cancellaria at Rome too quickly. Michelangelo's withering comment on being told that they had been finished in a hundred days ("e si vedi") directly echoed that of Apelles. However, the same theoretical tradition certainly championed works showing the kind of lightness of touch which merely suggested quickness of execution. […] And yet this modern lightness of touch was not to be confused with mere time-saving.
(Tom Nichols, Tintoretto: Tradition and Identity (1999))
We involve ourselves in endless perplexities in trying to deduce excellence and beauty, unity and necessity, from the describable qualities of things, we repeat the rationalistic fiction of turning the notions which we abstract from the observation of facts into the powers that give those facts character and being.
(George Santayana, The Sense of Beauty (1896))