Authors:
  • These rough sketches, which are born in an instant in the heat of inspiration, express the idea of their author in a few strokes, while on the other hand too much effort and diligence sometimes saps the vitality and powers of those who never know when to leave off.

    "The Lives of the Painters, Sculptors, and Architects". Book by Giorgio Vasari, Volume 2. p. 28, 1900.