kings, 440-360 B.C. Cp. Cic. ad Fam. v. 12.
_Socrates._ Cp. Diog. Laert. ii. 5, 33.
_Demosthenes_ and _Plato_. Cp. Quint. xii. 2. 22 and 10. 23.
_Eubulides_, a sophist of Miletus. Cp. Diog. Laert. ii. 10. 4.
_the orator when he wrangles_, &c. The pun on _iurgari_, 'wrangles,'
and _obiurgari_, 'rebukes,' can scarcely be reproduced. 'Disproves'
and 'disapproves' would weaken the translation.
_Epicurus_ of Samos, born 342 B.C. For his views on vision cp. Lucret.
iv. 156, on mirrors, 293.
_Plato._ Cp. Timaeus, p. 46 A, 'Within the eyes they (the gods)
planted that variety of fire which does not burn, but it is called
light homogeneous with the light without. We are enabled to see in the
daytime, because the light within our eyes pours out through the
centre of them and commingles with the light without. The two being
thus confounded together transmit movements from every object they
touch through the eye inward to the soul, and thus bring about the
sensation of the sight.' Grote's Plato iii. 265.
_Archytas_ of Tarentum, a Pythagorean (circa 400 B.C.). _The
Stoics_--believed that sight consisted in a refined fluid or visual
effluence proceeding from the central intelligence through the eyes.
'In the process of seeing, the [Greek: horatikon pneuma] (visual
effluence) coming into the eyes from the [Greek: hegemonikon] (central
intelligence) gives a spherical form to the air before the eye by
virtue of its [Greek: tonike kinesis] (i.e. the tension it sets up),
and by means of the sphere of air comes in contact with things; and
since by this process rays of light emanate from the eye, darkness
must be visible.' Zeller, The Stoics, Epicureans, and Sceptics, p.
209, note. Cp. Plut. Plac. Phil. iv. 15.