Calvin In Context, quote.. from the book by David Steinmetz.
“The problem of the natural knowledge of God in Calvin’s theology was sharply posed in the 1930′s in a famous debate between Karl Barth and Emil Brunner. In a little book, Natur and Gnade, Brunner argued for what he called a “Christian natural theology.” By the use of this somewhat ambiguous phrase, Brunner meant to suggest that the image of God had not been completely destroyed by human sin and disobedience. Remnants of the image were still present in human nature and formed a point of contact for the gospel. Furthermore, the revelation of God in nature was not lost to Christians, who, by using the spectacles of Scripture, could once again know God in and through his works. In all these contentions Brunner claimed Calvin as his ally and mentor.
Calvin considers this remnant of the imago Dei to be of great importance. One might almost say it is one of the pillars supporting his theology, for it identifies it with nothing less than the entire human, rational nature, the immortal soul, the capacity for culture, the conscience, responsibility, the relation with God, which – though not redemptive – exists even in sin, language, the whole of cultural life.” (Emil Brunner and Karl Barth, Natural Theology, trans. Peter Fraenkel (LondonL Geoffrey Bles, 1946), p. 37.) – Calvin, in Context, David Steinmetz, Second Edition Oxford, 2010, p. 23.