Turkish War part 21
However he never ceased caring for Diogenes, and was heard to sigh deeply for him; he displayed great kindness towards him and tried to console him and reinstated him in most of the possessions of which he had been deprived. But Diogenes was frantic with grief, detested town-life and was fond of living on his own estate and devoting himself entirely to the works of the ancient writers which others read aloud to him. For as he was bereft of sight he used the eyes of others for reading. He was a man of such wonderful capabilities that even without eyes he easily understood things that people with eyes find difficult to follow.
Figures of geometry
Then he went through all the later learning, and what is strangest, he even studied that famous science, geometry, under the guidance of a philosopher, whom he ordered to get him the figures made in solid material (or in relief). For by feeling these all over with his hands he gained comprehension of all the theorems and