Leonardo says somewhere in MS. C.A.:  Architronito e una macchina di fino rame, invenzlon d’ Archimede (see ’Saggio’, p. 20).]

1477.

Aristotle, Book 3 of the Physics, and Albertus Magnus, and Thomas Aquinas and the others on the rebound of bodies, in the 7th on Physics, on heaven and earth.

1478.

Aristotle says that if a force can move a body a given distance in a given time, the same force will move half the same body twice as far in the same time.

1479.

Aristotle in Book 3 of the Ethics:  Man merits praise or blame solely in such matters as lie within his option to do or not to do.

1480.

Aristotle says that every body tends to maintain its nature.

1481.

On the increase of the Nile, a small book by Aristotle. [Footnote:  De inundatione Nili, is quoted here and by others as a work of Aristotle.  The Greek original is lost, but a Latin version of the beginning exists (Arist.  Opp.  IV p. 213 ed.  Did.  Par.).

In his quotations from Aristotle Leonardo possibly refers to one of the following editions:  Aristotelis libri IV de coelo et mundo; de anima libri III; libri VIII physi- corum; libri de generatione et corruptione; de sensu et sensato... omnia latine, interprete Averroe, Venetiis 1483 (first Latin edition).  There is also a separate edition of Liber de coelo et mundo, dated 1473.]

1482.

Avicenna will have it that soul gives birth to soul as body to body, and each member to itself.

[Footnote:  Avicenna, see too No. 1421, 1. 2.]

1483.

Avicenna on liquids.

1484.

Roger Bacon, done in print. [Footnote:  The earliest printed edition known to Brunet of the works of Roger Bacon, is a French translation, which appeared about fourty years after Leonardo’s death.]

1485.

Cleomedes the philosopher.

[Footnote:  Cleomede.  A Greek mathematician of the IVth century B. C. We have a Cyclic theory of Meteorica by him.  His works were not published before Leonardo’s death.]

1486.

CORNELIUS CELSUS.

The highest good is wisdom, the chief evil is suffering in the body.  Because, as we are composed of two things, that is soul and body, of which the first is the better, the body is the inferior; wisdom belongs to the better part, and the chief evil belongs to the worse part and is the worst of all.  As the best thing of all in the soul is wisdom, so the worst in the body is suffering.  Therefore just as bodily pain is the chief evil, wisdom is the chief good of the soul, that is with the wise man; and nothing else can be compared with it.

[Footnote:  Aulus Cornelius Celsus, a Roman physician, known as the Roman Hippocrates, probably contemporary with Augustus.  Only his eight Books ‘De Medicina’, are preserved.  The earliest editions are:  Cornelius Celsus, de medicina libr.  VIII., Milan 1481 Venice 1493 and 1497.]