Citations of Leonardo’s manuscripts refer to the scholarly editions listed in the Bibliography. Most of these editions are now available also online at e-Leo (), published by the Biblioteca Leonardiana in Vinci. I have retranslated some of the passages by staying closer to the original Italian texts to preserve their Leonardesque flavor.
1. See Murray, Genius.
2. See Steptoe, Genius and the Mind.
3. See David Lykken, “The Genetics of Genius,” in Steptoe, Genius and the Mind.