In order to finish this someday (and hopefully one soon as Defense of the Faith and Christian Apologetics continue to creep higher on my too read and comment on list) here is the next section of discussion on Van Til's Introduction to Systematic Theology. I'm going to just do one chapter at a time from here on out so that it will be in more manageable blocks. There are three chapters after this on God's incommunicable attributes and names, the Trinity, and God's communicable attributes.
Chapter 15 – Innate and Acquired Knowledge of God
This brief chapter examines how it is that we come to know God. This is built upon the same principles that Van Til examined under Christian epistemology. In spite of himself, man must recognize that he has the knowledge of God within him. God’s general revelation is constantly before the sinner no matter how much he tries to suppress it and keep it down. God does not create the mind of man as a tabula rasa (empty slate). Adam immediately reacted ethically to the innate knowledge of God and fallen man cannot stop reacting ethically to that knowledge.
Van Til then questions what it means for man to have an innate knowledge of God. He critiques Bavinck here. Bavinck occasionally suggests that innate knowledge really means a capacity for knowledge. That capacity implies that when a man sees the light of the sun he must know that there is a God and that there is a difference between good and evil. Van Til argues that this does not give a complete picture. It does not have any regard for the reaction of man to that revelation and does not give any content to good or to evil. It is not enough for man to know that God is but he must also worship God as Creator.
Van Til therefore turns to discuss the common theological proofs and their value in witness and apologetics. He argues that “there is no essential difference between witnessing and proving.” (317) The Christian witness is his apologetic and the Christian must always go forward secure in the knowledge that he has the truth and that his opponents trust in a lie. Yet these proofs often betray that principle as they seek to find agreement with the unbeliever and to proceed from there. Van Til does not believe that this agreement is possible (though he does believe that there are points of contact to open discussions). So it is not enough to move forward on the basis of innate knowledge of God and assume that there are general principles upon which Christians and non-Christians are agreed. There are no such general principles because the worldviews and presuppositions behind how both come to a conclusion are so different. In making this case Van Til is simply applying the doctrine of total depravity to apologetics. Fallen man is also depraved in his thinking and though God’s revelatory activity means that he knows there is a God it also illustrates his sin as he rejects that conclusion and flees to other presuppositions for the things that are.
Therefore, Van Til agrees with Bavinck that no one, not even the Christian, can read nature rightly apart from the light of Scripture. The difference between the Christian and the non-Christian is that the Christian knows and accepts this truth. The Christian believes that he would interpret nature wrongly apart from Scripture and the Holy Spirit. So for the Christian to appeal to the unbeliever that nature proves the existence of God means that he must do so on the clear understanding that he is interpreting nature in light of Scripture.
This leads Van Til to conclude that, “The innate and the acquired knowledge of God may, accordingly, be said to be correlative to one another.” The innate knowledge of God does not save because total depravity means we interpret the facts and revelation wrongly. Fallen men can only acquire knowledge of God from the Holy Spirit speaking through Scripture. Acquired knowledge of God through Scripture then leads to right interpreting of the innate knowledge of God.