A Treatise on Painting
by Leonardo da Vinci, translated by John Francis Rigaud
Which of the two is the most useful Knowledge, the Outlines of Figures, or that of Light and Shadow
4009409A Treatise on Painting — Which of the two is the most useful Knowledge, the Outlines of Figures, or that of Light and ShadowJohn Francis RigaudLeonardo da Vinci

Chap. CLXXVI.Which of the two is the most useful Knowledge, the Outlines of Figures, or that of Light and Shadow.

The knowledge of the outline is of most consequence, and yet may be acquired to great certainty by dint of study; as the outlines of the different parts of the human figure, particularly those which do not bend, are invariably the same. But the knowledge of the situation, quality, and quantity of shadows, being infinite, requires the most extensive study.