Faith and charity depend on man's will, yet so that the habits of these and other virtues require the power of the will which is in children; whereas acts of virtue require an act of the will, which is not in children.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic virtue faith
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/19950/pg19950-images.html

Context

“But this inability of children to act is not due to the absence of habits, but to an impediment on the part of the body: thus also when a man is asleep, though he may have the habits of virtue, yet is he hindered from virtuous acts through being asleep. Reply Obj. 1: Faith and charity depend on man's will, yet so that the habits of these and other virtues require the power of the will which is in children; whereas acts of virtue require an act of the will, which is not in children. In this sense Augustine says in the book on Infant Baptism (Ep. xcviii) : "The little child is made a believer, not as yet by that faith which depends on the will of the believer, but by the sacrament of faith itself,"” source