For the want of sight is not an evil in a stone, but it is an evil in an animal
 Thomas Aquinas, Summa Theologica (1274). copy citation

add
Author Thomas Aquinas
Source Summa Theologica
Topic evil sight
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17611/pg17611-images.html

Context

“Reply Obj. 1: Because evil is the privation of good, and not a mere negation, as was said above (A. 3) , therefore not every defect of good is an evil, but the defect of the good which is naturally due. For the want of sight is not an evil in a stone, but it is an evil in an animal; since it is against the nature of a stone to see. So, likewise, it is against the nature of a creature to be preserved in existence by itself, because existence and conservation come from one and the same source.” source