For it is the mind which is entertained by what we see; but the mind may be entertained in many ways, even though we could not see at all.

I am speaking of a learned and a wise man, with whom to think is to live.

But thinking in the case of a wise man does not altogether require the use of his eyes in his investigations; for if night does not strip him of his happiness, why should blindness, which resembles night, have that effect?
For the reply of Antipater the Cyrenaic to some women who bewailed his being blind, though it is a little too obscene, is not without its significance.

"What do you mean ?" saith he; "do you think the night can furnish no pleasure ?" And we find by his magistracies and his actions that old Appius,[70] too, who was blind for many years, was not prevented from doing whatever was required of him with respect either to the republic or his own affairs.
It is said that C.Drusus's house was crowded with clients.

When they whose business it was could not see how to conduct themselves, they applied to a blind guide.
XXXIX.