SOURCE: "Calvin, Luther, and Zwingli," in The Theology of John Calvin, translated by Geoffrey W. Bromiley, William B. Eerdmans Publishing Company, 1995, pp. 69–128.

In this excerpt from his noted study of Calvin, originally published in 1922, Barth discusses Zwingli's thought in relation to that of both Calvin and Luther.

In taking Calvin as the specifically and typically Reformed reformer as distinct from Luther, what I have in mind is that because of Zwingli's early death we have only Calvin's and not Zwingli's Reformed theology before us in developed systematic form, and it was Calvin, not Zwingli, who in large part left his imprint on the Reformed world. For a proper understanding of Calvin, however, we must not overlook the fact that the so-to-speak classical representative of the Reformed possibility was Zwingli. In a pure, one-sided, not too cautious, and very exposed form, the Reformed trend is much more prominent in...