Sight-seeing becomes sinful, when it renders a man prone to the vices of lust and cruelty on account of things he sees represented.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic cruelty vice
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/18755/pg18755-images.html

Context

“for pleasure seeketh objects beautiful, melodious, fragrant, savory, soft; but curiosity, for trial's sake, seeketh even the contraries of these, not for the sake of suffering annoyance, but out of the lust of experiment and knowledge." Reply Obj. 2: Sight-seeing becomes sinful, when it renders a man prone to the vices of lust and cruelty on account of things he sees represented. Hence Chrysostom says [*Hom. vi in Matth.] that such sights make men adulterers and shameless. Reply Obj. 3: One may watch other people's actions or inquire into them, with a good intent, either for one's own good—that is in order to be encouraged to better deeds by the deeds of our neighbor—or for our neighbor's good—that is in order to correct him, if he do anything wrong, according to the rule of charity and the duty of one's position.” source