His Institutio Theologiae Elencticae was the culmination of Reformed scholasticism. The Institutes uses the scholastic method to dispute a number of controversial issues. In it he defended the view that the Bible is God's verbally inspired word. He also argued for infralapsarianism and federal theology. The Institutes was widely used as a textbook, up to its use at Princeton Theological Seminary by the Princeton theologians only to be replaced by Charles Hodge's Systematic Theology in the late 19th century. Of his other disputations, his most important are De Satisfactione Christi disputationes and De necessaria secessione nostra ab Ecclesia Romana et impossibili cum ea syncretismo. He wrote the Helvetic Consensus, a Reformed confession written against Amyraldianism, with J. H. Heidegger in 1675. Turrettini greatly influenced the Puritans, but until recently, he was a mostly forgotten Protestant scholastic from the annals of church history, though the English translation of his Institutes of Elenctic Theology is increasingly read by students of theology. John Gerstner called Turrettini "the most precise theologian in the Calvinistic tradition."
Free Choice
Along the lines of Reformed theology, Turrettini argues that after the fall human beings did not lose the faculty of will itself. "The inability to do good is strongly asserted, but the essence of freedom is not destroyed". They still have liberty which is not repugnant to certain kinds of necessity. Turrettini distinguishes six kinds of necessity : physical necessity, necessity of coercion, necessity of dependence on God, rational necessity, moral necessity, and necessity of event. The first two among these six necessities are incompatible with freedom, whereas the latter four are not only compatible with freedom but perfect it. For Turrettini, freedom does not arise from an indifference of the will. No rational beings are indifferent to good and evil. The will of an individual human being is never indifferent in the sense of possessing an equilibrium, either before or after the fall. Turrettini defines freedom with the notion of rational spontaneity. Turrettini's doctrine of freedom appears to be similar to that of Scotus in that both of them endorse Aristotelian logic: the distinction between the necessity of the consequent and the necessity of the consequence ; the distinction between in sensu composito and in sensu diviso. It is not Scotus's notion of synchronic contingency but Aristotle's modal logic which is incorporated into Turrettini's doctrine of freedom. Moreover, the Scotistic ideas about necessity and indifference differ greatly from those of Turrettini. Turrettini develops the discussion on necessity and relates it to his argument about human freedom of choice. His careful rejection of the notion of indifference in the doctrine of freedom creates a big gap between his doctrine and that of Scotus. Turrettini's teaching of contingency emphasizes the sovereign act of God in the process of conversion, whereas Scotus's contingency theory blurs it. Turrettini is not a Scotist, but a Reformed theologian standing in a more “generic Aristotelian tradition.”
English translations
Institutes of Elenctic Theology. Translated by George Musgrave Giger, edited by James T. Dennison, Jr..
Justification an excerpt from Turretin's Institutes.
The Atonement of Christ. Translated by James R. Willson.
