In chapter nine, In Defense of Theistic Arguments, Groothius states that natural theology consists of theistic arguments (sometimes called theistic proofs). They are rational arguments for the existence of a monotheistic God that do not appeal to sacred scriptures for their cogency.
Argument Forms
Theistic proofs are the product of natural theology and is distinguished from revealed theology.
Types of Theistic Arguments
Theistic proofs are grouped into two categories. The first, is a posteriori or empirical arguments, such as, the cosmological, design, moral, and religious experience arguments. The second, is the a priori. These arguments rely on what is rationally known apart from the empirical world. The ontological argument falls into this category.
While General revelation as taught in Romans 1:19-20 is necessary for natural theology, it is not sufficient. Nor are these two terms synonymous. General revelation means that God has revealed himself in nature and conscience. Natural theology engages in logic in order to derive rational arguments for God’s existence.
Nine Objections to Natural Theology
These objections can be divided into two categories. The first is in-principle objections which claim there is something intrinsically wrong with theistic arguments.
1. Biblical omission argument. Pascal argued that since Scripture presents no natural theology we should also not use it. The counter argument is that atheism, which natural theology primarily refutes, was not an issue in Bible times. False religions were polytheistic or pantheistic not atheistic.
2. Biblical authority argument. Scholars like Van Till argue that since the Bible is the ultimate authority on God, its claim that God exists needs no external support. Groothius argues that proving the authority of the bible does not lessen its authority with those who reject the authority of the Bible.
3. The noetic effects of sin argument. Another in-principle argument is that human reason is too corrupted by sin to warrant any hope of proving God’s existence. Part of being made in the image of God is being able to think and reason as God does. So, though fallen, man can still reflect the image of God by thinking logically.
4. Direct knowledge of God argument. Both Kiekegaard and Van Tillian presuppositionalists have argued that to attempt to argue for God’s existence is radically inappropriate because people have a direct awareness of God that requires no proof.
It is true that every sinner is without excuse, Romans 1:20, because God has revealed Himself through creation and conscience (Romans 2:18-20). Yet is also true that this divine intuition is suppressed by every sinners (Romans 1:18) and therefore theistic arguments have been used by God in the sinner’s life.
5. Proofs lead to pride argument. Paschal claims that successful theistic arguments that have nothing to do with the incarnation would engender pride in those who engage in them. Paschal passionately wants to convince people of their moral and spiritual need for redemption offered by Jesus Christ. In light of this he worries that natural theology proves a God without Christ, which might undermine the sense of “wretchedness” that he seeks to demonstrated about the human condition.
However, natural theology may help someone know that God exists, and if that person moves from atheism to theism, he or she may then begin to investigate the claims and credentials of Christian theism.
6. Natural theology in competition with special revelation argument. Karl Barth forcefully rejected natural theology because he took it to be in competition with the revelation of Scripture.
However, a right understanding of general revelation and natural theology is no threat to special revelation. Further, a sound apologetic method attempts to verify the Christian worldview through various means, not merely by natural theology.
The second category for objections is in-practice arguments against natural theology.
7. Religious irrelevance argument. Some object that while the idea of natural theology is not wrong in itself, the arguments do not secure enough knowledge about the character of God. Natural theology has the potential of leading person to belief in God and the possibility of Christianity being credible.
If Jane is argued out of atheism by one or more arguments from natural theology, she may become interested in evaluating the specifically Christian claims about God and Christ found in the Bible.
Natural theology in the Christian tradition has never been regarded as an end in itself but rather as a prelude to other evidences.
8. Complexity of proofs argument. Pascal and others also complain about the complexity of theistic arguments. I agree that these arguments are so complex they are hard to understand and therefore useless in arguing for the existence of God.
9. Rational weakness argument. Groothius gives three reasons theistic arguments are rejected. What is true for theistic arguments is also true for the gospel. Both are rejected but doesn’t mean we stop presenting them.