Man is said to have lost free-will by falling into sin, not as to natural liberty, which is freedom from coercion, but as regards freedom from fault and unhappiness.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic unhappiness freedom
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

“But Bernard takes habit, not as divided against power, but as signifying a certain aptitude by which a man has some sort of relation to an act. And this may be both by a power and by a habit: for by a power man is, as it were, empowered to do the action, and by the habit he is apt to act well or ill. Reply Obj. 3: Man is said to have lost free-will by falling into sin, not as to natural liberty, which is freedom from coercion, but as regards freedom from fault and unhappiness. Of this we shall treat later in the treatise on Morals in the second part of this work (I-II, Q. 85, seqq.; Q. 109) . _______________________ THIRD ARTICLE [I, Q. 83, Art. 3] Whether Free-will Is an Appetitive Power?” source