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 suf-fering. 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.]
Tr. 57]
1487.
Demetrius was wont to say that there was no difference between the speech and words of the foolish and ignorant, and the noises and rumblings of the wind in an inflated stomach. Nor did he say so without reason, for he saw no difference between the parts whence the noise issued; whether their lower parts or their mouth, since one and the other were of equal use and importance. [Footnote: Compare Vol. I, No. 10.] S.K.M. III.93a]
1488.
Maestro Stefano Caponi, a physician, lives at the piscina, and has Euclid De Ponderibus.
K.2 2a]
1489.
5th Book of Euclid. First definition: a part is a quantity of less magnitude than the greater magnitude when the less is contained a certain number of times in the greater.
A part properly speaking is that which may be multiplied, that is when, being multiplied by a certain number, it forms exactly the whole. A common aggregate part …
Second definition. A greater magnitude is said to be a multiple of a less, when the greater is measured by the less.
By the first we define the lesser [magnitude] and by the second the greater is defined. A part is spoken
K.2 2b]
1490.
of in relation to the whole; and all their relations lie between these two extremes, and are called multiples.
S.K.M.III. 16b]
1491.
Hippocrates says that the origin of men's sperm derives from the brain, and from the lungs and testicles of our parents, where the final decocture is made, and all the other limbs transmit their substance to this sperm by means of expiration, because there are no channels through which they might come to the sperm. [Footnote: The works of Hippocrates were printed first after Leonardo's death.] Ash.II. IIb]
1492.
Lucretius in his third [book] 'De Rerum Natura'. The hands, nails and teeth were (165) the weapons of ancient man.
They also use for a standard a bunch of grass tied to a pole (167). [Footnote: Lucretius, de rerum natura libri VI were printed first about 1473, at Verona in 1486, at Brescia in 1495, at Venice in 1500 and in 1515, and at Florence in 1515. The numbers 165 and 167 noted by Leonardo at the end of the two passages seem to indicate pages, but if so, none of the editions just mentioned can here be meant, nor do these numbers refer to the verses in the poems of Lucretius.]
Tr. 2]
1493.
Ammianus Marcellinus asserts that seven hundred thousand volumes of books were burnt in the siege of Alexandria in the time of Julius Cesar. [Footnote: Ammiani Marcellini historiarum libri qui extant XIII, published at Rome in 1474.]
Tr. 2]