Aquinas

Abstract

Aquinas develops Aristotelian themes as a foundation for his account of the Christian virtues. The will is both rational, being directed towards the ultimate good, and free, being determined by practical reason about what contributes to the ultimate good. Virtue is the good use of free will; it requires both the appropriate training of the passions (the non-rational part of the soul) and the correct practical reason. Practical reason finds the first principles of the natural law (the rational principles that are suitable for human nature), and the action-guiding rules that specify the implications of the natural law for human beings with a social nature, and for human society. The virtues, embodying the natural law, guide us towards the good that is proper to human beings. They do not guide us all the way, because we are subject to the influence of the sins that turn us away from God. Divine grace moves our free will to overcome the effects of these sins, and to form the Christian virtues that lead us towards the complete good.