<I>God the Father in the Theology of St. Thomas Aquinas</I> is an exposition of Aquinas¿ theology of God the Father as a coherent whole. Surprising as it might be, there has not been an extended treatment of Aquinas¿ theology of God the Father. Three misconceptions are addressed: (1) the idea that Aquinas¿ speculative Trinitarian theology is detached from Scripture; (2) the supposition that in Aquinas¿ understanding, the Father¿s relation to the Holy Spirit is an afterthought to the Father¿s relation to the Son; and (3) the view that for Thomas, the Father has no proper mode of action in the created universe ¿ since Thomas maintains that in all <I>ad extra</I> activity, the Trinity acts as a single principle. Two less polemical, more perennial issues are discussed as well. First, the concept of relation, as the key to a coherent account of three distinct persons in one same divine essence, emerges as an important theme in Aquinas¿ exposition of the Father¿s paternity and innascibility.