The Master has taken in hand a treatise on painting; the Lord knows when he will finish it. Latterly he has been much busied (I likewise, helping him) with aerial and line perspective, both in light and shade, and he has given me discourses and fugitive thoughts upon art. I will now write down such as I can remember of the noblest of sciences; and may those into whose hands these pages shall fall, remember in their prayers the soul of the great Florentine master, Leonardo da Vinci, and the soul of Giovanni Boltraffio, his humble disciple.
The Master says 'All which is beautiful, even humanly beautiful, dies, except in art. (Cosa bella mortal passa e non d'arte.)
'He who despises painting despises the philosophical and refined contemplation of the world. Painting is the grandchild of Nature and the kinswoman of God.'
'Il pittore deve essere universale. O painter, be thy variety infinite as the phenomena of Nature! Carrying on what God has begun, seek to multiply, not the works of men's hands, but those of the eternal hands of God. Imitate no one; let thy every work be a new phenomenon of Nature.'
'For him who is master of the fundamental natural laws; for him who knows, it is easy to be universal; because all bodies, whether of men or of beasts, are really formed on the same principles.'
'Take heed lest in thee the greed for gold suffocate the love of art; and remember that the conquest of glory excels the glory of conquest. The memory of the rich perishes with them, the memory of the wise endures for ever; because science and wisdom are the legitimate children of their father, and money is but his bastard. Love glory, and be not fearful of poverty. Consider how many philosophers have laid down the wealth to which they were born, that they might enrich their souls with virtue, and have lived content in misery.'