Sin in Human Act : Remarks on Thomas Aquinas' Definition of Sin

The purpose of this essay is to bring out the intention of Thomas Aquinas when he uses the concept of sin in a wide sense which means not only to do something wrong but also to fail to act in accord with the perfect paradigm of human action in any situation. The author's argument is divided into three stages. In the first place he examines how Aquinas' definition of sin works when it is applied to the case where sin is committed by negligence or through mere carelessness without having any intention to do something wrong. Secondly he introduces the concept of human act as a clue to understand the concept of sin, and suggests that the concept of human act should cover not only the physical but also the moral acts which are both intellectual and voluntary. Then the author examines the concept of perfect human act and concludes that the perfect examplar of human act should, at every moment, be looked for and found out by the actor himself, and that the act of inquiring and finding it is based on the liberty of action which human beings are endowed with