But the good of nature is wholly uniform. Since therefore a part thereof can be taken away by sin, it seems that the whole can also be taken away by sin.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic sin good
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/17897/pg17897-images.html

Context

“Since therefore the good of nature can be continually diminished by sin, it seems that in the end it can be entirely taken away.
Obj. 2: Further, in a thing of one nature, the whole and the parts are uniform, as is evidently the case with air, water, flesh and all bodies with similar parts. But the good of nature is wholly uniform. Since therefore a part thereof can be taken away by sin, it seems that the whole can also be taken away by sin. Obj. 3: Further, the good of nature, that is weakened by sin, is aptitude for virtue. Now this aptitude is destroyed entirely in some on account of sin: thus the lost cannot be restored to virtue any more than the blind can to sight.” source