 For Aquinas, the rational part of the soul comprises the faculties or powers of intellect and will. The object of the will is the good, and the object of the intellect is the true. The latter potency is further divided into the speculative intellect (intellectus speculativus) and the practical intellect (intellectus practicus). How do these differ? The object of the speculative intellect is truth as such, while the object of the practical intellect is the good “under the aspect of truth” (Thomas Aquinas, Summa theologica I, q. 79, a. 11, ad. 2). Synderesis and conscience, for Aquinas, both belong to the practical intellect.