Abstract

Thomas' theory of sin is a specification of his general theory of metaphysical evil. Both his theory of evil in general and his theory of moral evil specifically provide an understanding that constitutes a scientia, for both theories consist of an explanation of the four causes of evil. As a contrary of good, evil can be explained by means of its causes, for the scientia of good includes the understanding of the contrary of good. Thus sin can be understood precisely as it is opposed to the good proper to rational creatures. ;The fact that Thomas's theory of evil consists of an explanation of its four causes is most evident in his Disputed Questions De malo. Thomas' explanation of moral evil parallels his explanation of metaphysical evil, as it demonstrates the four causes of sin in a similar fashion. Further, Thomas' theory of metaphysical evil provides the foundation for his explanation of moral evil; thus Thomas will apply the principles established concerning evil in general to the particular difficulties that arise in regard to the evil found in the rational creature. ;In his general theory of evil, Thomas determined that evil itself was not a thing, for there is no form or end proper to an evil nature. Evil can be understood according to the form that it opposes, and it is only found in some subject that properly possesses that form. Something that acts according to its end as a final cause may be the efficient cause of evil, either deficiently as it or the matter it acts upon is deficient, or as the good it acts for is accidentally an evil to another. The particular good that the efficient cause of evil intends or acts for, then, is a particular good that is in some way contrary to the particular good of some creature. In the case of sin, the will is the efficient cause of evil, as it intends something good, but there is some evil joined to it either accidentally or through its deficiency. Moral evil, then, is known by way of these causes