This will be a straightforward post, but I wanted to take a moment to highlight how the Post-Reformed orthodox come to their affirmation of natural theology. It is important to qualify this, though, in the sense that the PRO believe that natural theology is actually a sub-category of special revelation; at least for the Christian, and it is this aspect of natural theology that we will be
sketching with reference to Richard Muller’s development of it.
Here is Richard Muller’s take on natural theology in Post-Reformed orthodox theology; he has been developing quite a bit previous to what I am going to quote, and we will jump in just as he is citing how Francis Turretin offers a mediating way for understanding how it is at an epistemological level that human agents can have a natural knowledge of God.
Thus Turretin can say that the human mind is not a tabula rasa absolutely but only relatively: it does not naturally contain discursive or dianoetic knowledge (cognitio dianoetica), that is, acquired knowledge, but it does contain noesis or pure intellectual apprehension (cognitio insita or cognitio apprehensiva et noetica).
Using this concept of cognitio insita or cognitio intuitiva sive apprehensiva, the Reformed orthodox can argue three basic forms of natural theology, two of them arising immediately and universally in the human mind and one arising as a result of rational examination of others. First, the universal experience of mankind and the institution of religion in every nation of the world indicates a sense of the divine or of divine power (sensus numinis). There is no nation so barbaric, Cicero declared, that it is not persuaded of the existence of God. Second, the human conscience bears witness to a natural law which, Turretin concludes, “necessarily includes a knowledge of God the Lawgiver (cognitio Dei Legislatoris).” Knowledge of God, in other words, arises naturally from the contemplation of created things and by inference from the order and government of things. Third, out of these basic apprehensions of the divine, by means of purely rational investigation, pagan philosophers have developed a philosophical natural theology, an acquired natural theology.
In a nutshell this is how ‘natural theology’ is established for the Post-Reformed orthodox. Indeed, it is this kind of thinking that funds most evangelical thought in general in regard to a belief in a natural possibility for knowledge of God.
Unfortunately these building blocks are often taken as positive and even fundamental things that end up getting integrated into a total theology; inclusive of special revelation. In other words, these inferences about God from nature, in a categorical way, end up getting deployed by the classically Reformed and evangelical Christian in such a way that the God inferred in nature gets synthesized by the active intellect with the God revealed in Scripture and Jesus Christ resulting in the total picture of God (in an ectypal sense). The basic problem to this procedure is that the go-between between the God inferred in nature and the God revealed in Scripture and Jesus Christ is our minds, and our hands. It is left up to us to unite the works of God (inferred from nature) with the person of God revealed in Jesus Christ. At an epistemic level then God is betokened to our behest; this is one reason Karl Barth (in response to Post-Reformed orthodox machinations as well as more close to home for him, the Nazis deployment of their sinister appropriation and form of ‘natural theology’ in a social-Darwinian sense) repudiated natural theology and the analogy of being. I.e. it makes revelation something dependent upon human wits, and leaves no space for God to truly confront us in His Self-revelation and interpreting Word in Jesus Christ and Scripture.
 It is also important to highlight that the Post-Reformed Orthodox do believe that there is universal, general natural knowledge of God available, but that apart from Jesus Christ it is only enough knowledge to condemn them and not to save them, nor to give an accurate knowledge of God.
 Richard A. Muller, Post-Reformation Reformed Dogmatics (Grand Rapids, Michigan: Baker Academic, 2003), 285-86.