“The charge is made that we engage in circular reasoning. Now if it be called circular reasoning when we hold it necessary to presuppose the existence of God, we are not ashamed of it because we are firmly convinced that all forms of reasoning that leave God out of account will end in ruin. Yet we hold that our reasoning cannot fairly be called circular reasoning, because we are not reasoning about and seeking to explain facts by assuming the existence and meaning of certain other facts on the same level of being with the facts we are investigating, and then explaining these facts in turn by the facts with which we began. We are presupposing God, not merely another fact of the universe. If God is to come into contact with us at all it is natural that the initiative must be with him. And this will also apply to the very question about the relation of God to us. Accordingly, it is only on God’s own testimony that we can know anything about him.”
– Cornelius Van Til, A Survey of Christian Epistemology p.201
See also: The Charge of Circular Reasoning and Spiral Reasoning
“For this reason we have spoken of the Christian theistic method as the method of implication into the truth of God. It is reasoning in a spiral fashion rather than in a linear fashion. Accordingly, we have said that we can use the old terms deduction and induction if only we remember that they must be thought of as elements in this one process of implication into the truth of God. If we begin the course of spiral reasoning at any point in the finite universe, as we must because that is the proximate starting point of all reasoning, we can call the method of implication into the truth of God a transcendental method. That is, we must seek to determine what presuppositions are necessary to any object of knowledge in order that it may be intelligible to us. It is not as though we already know some facts and laws to begin with, irrespective of the existence of God, in order then to reason from such a beginning to further conclusions. It is certainly true that if God has any significance for any object of knowledge at all, the relation of God to that object of knowledge must be taken into consideration from the outset. It is this fact that the transcendental method seeks to recognize.”
– Cornelius Van Til, A Survey of Christian Epistemology p.201
“With such as these it would seem that the point we should be most anxious to drive home is that in trying to be agnostic, and in trying to say that they have no need of metaphysics, they have already given one of the two possible answers to every question of epistemology that may be asked. They have, as a matter of fact, said that all the facts—or, in epistemological language, they have said that the object and the subject of knowledge—exist apart from God and are able to get along without God. They think they have said nothing at all about ultimate matters, while as a matter of fact they have in effect said everything that could be said about them, and, we believe, more beside. They have tried to be so modest that they did not dare to make a positive statement about anything ultimate, while they have made a universal negative statement about the most ultimate consideration that faces the mind of man. That this charge is fair is apparent from the consideration of the opposite. Suppose that the object and the subject of knowledge do not exist apart from God. Suppose, in other words, that the Christian theistic conception of philosophy is true. In that case, it is not only possible to know something about ultimate things, but in that case the knowledge of proximate things depends upon the knowledge of ultimate things. In that case, not a single fact can be known unless God is known.
What the present-day agnostic should do then is to make his position reasonable by showing that God does not exist. The burden of the proof is upon him. He claims, of course, that the burden of the proof is upon us when we hold that God exists. Yet this is clearly not the case, since his own position, to be reasonable, must presuppose the non-existence of God. If God does exist, man can know him, for the simple reason that in that case all knowledge depends upon him. Hence an agnostic position must first prove that God does not exist.
From these considerations it follows that agnosticism is completely self-contradictory. And it is self-contradictory not only upon the assumption of the truth of theism, but it is self-contradictory upon the assumption of the truth of antitheism, which is the assumption of agnosticism.”
– Cornelius Van Til, A Survey of Christian Epistemology p.212-213
We may contrast this doctrine of the Trinity with Plato’s thought by calling attention to the fact that for Augustine the Trinity furnished the basis of the principles of unity and diversity in human knowledge. In other words the Trinity is for Augustine as for all orthodox Christians a conception without which knowledge were impossible to man. That there is plurality which man must seek to relate to some underlying unity, is patent to all men. From the earliest dawn of reflective thinking it has been the effort of man to find unity in multiplicity. But the difficulties that meet one when trying to speculate upon the question of unity and plurality are that if one begins with an ultimate plurality in the world, or we may say by regarding plurality as ultimate, there is no way of ever coming to an equally fundamental unity. On the other hand, if one should begin with the assumption of an ultimate abstract, impersonal unity, one cannot account for the fact of plurality. No system of thought can escape this dilemma. No system of thought has escaped this dilemma. Many systems of thought have denied one of the horns of the dilemma, but all that they have accomplished by doing this is to find relief in the policy of the ostrich.
What Augustine and all theistic thinkers after him have done is to say that in God, and more specifically in the triune God, lies the solution of this difficulty.
– Cornelius Van Til, A Survey of Christian Epistemology p. 47
If one maintains a soteriological theory in which the “natural man” is conceived of as able of his own accord to seek the truth because he has a true insight into his sorrowful condition, one cannot but become antitheistic epistemologically, in the sense that he must think of certain facts as existing in such a way that man can have knowledge of them without having knowledge of the true God. If no one can come to the Father but by Christ, and no one can say Christ to be Lord except through the Spirit, it is equally possible or equally impossible for man to come into contact with the Father or the Son or the Spirit. If one maintains that he can approach Christ of his own accord even if he is a sinner, he may as well say that he can approach the Father too. And if one can say that he knows what the fact of sin means without the enlightenment of the Holy Spirit, he may as well say that he can know other facts without reference to God. In fact he may as well say that he can know any and every fact without reference to God. If one fact can be known without reference to God there is no good reason to hold that not all facts can be known without reference to God. When the elephant of naturalism once has his nose in the door, he will not be satisfied until he is all the way in.
– Cornelius Van Til, A Survey of Christian Epistemology p.77
In consonance with this we may call attention to the fact that on the question of possibility the same difference of opinion exists that we found on the matter of predication. For the theist, possibility has its source in God, while for the antitheist, God has his source in possibility. Hence, what one will deem most possible, the other will consider altogether impossible.
Similarly, once more with the question of probability. For theism, God is the source of the probable. For antitheism, the probable is the source of God. Hence, what one thinks altogether probable, the other will think altogether improbable.
– Cornelius Van Til, A Survey of Christian Epistemology p.190
The final question, then, when considering the object of knowledge, is whether the spatial-temporal universe exists by itself or whether we must presuppose the existence of God in order to think intelligently of the spatial-temporal world. We found that, according to Christian theism, every individual object of knowledge to be known at all must be known in its relation to God. Then if one spatial object is to be known in its relation to another spatial object, the connection must be thought of as made by God. In other words, the universals of knowledge have their source in God. Similarly, if one object of knowledge is to be known in its relation to other objects of knowledge that have existed or will exist at another period of time, we must think of the connection as being made by the plan of God.
– Cornelius Van Til, A Survey of Christian Epistemology p.183
Since it is upon God’s command that the work must be undertaken, it is God’s command that gives one the assurance that the work will accomplish its purpose. Looking at matters by themselves, it would be worse than useless to undertake reasoning with unbelievers. But it is the deep conviction of the total depravity of man that makes one throw his whole reliance upon God in all respects, and not the least in this question of reasoning with unbelievers. It is only he who deeply believes in the total depravity of man that can really preach with conviction that his work will not be in vain. Since he is convinced that the ethical alienation has been against God and against nothing else, he also knows that God is able to remove the ethical alienation. He, therefore, trusts that the Holy Spirit to whom, in the economy of redemption, the task has been assigned of convicting the world of judgment, will use the means of rational argumentation to accomplish his task. This hope is not inconsistent with the conception of the immediacy of the work of the Holy Spirit. That immediacy is complete. Our arguments taken by themselves effect nothing, while the Holy Spirit may very well convict without the use of our argument as he may convict without the use of our preaching. Yet because God is himself a completely rational God and has created us in his image, there is every reason to believe that he will make argumentation effective.
– Cornelius Van Til, A Survey of Christian Epistemology p.196-197
We have already indicated that the Christian method uses neither the inductive nor the deductive method as understood by the opponents of Christianity, but that it has elements of both induction and of deduction in it, if these terms are understood in a Christian sense. Now when these two elements are combined, we have what is meant by a truly transcendental argument.
A truly transcendental argument takes any fact of experience which it wishes to investigate, and tries to determine what the presuppositions of such a fact must be, in order to make it what it is. An exclusively deductive argument would take an axiom such as that every cause must have an effect, and reason in a straight line from such an axiom, drawing all manner of conclusions about God and man. A purely inductive argument would begin with any fact and seek in a straight line for a cause of such an effect, and thus perhaps conclude that this universe must have had a cause. Both of these methods have been used, as we shall see, for the defense of Christianity. Yet neither of them could be thoroughly Christian unless they already presupposed God. Any method, as was pointed out above, that does not maintain that not a single fact can be known unless it be that God gives that fact meaning, is an anti-Christian method. On the other hand, if God is recognized as the only and the final explanation of any and every fact, neither the inductive nor the deductive method can any longer be used to the exclusion of the other. That this is the case can best be realized if we keep in mind that the God we contemplate is an absolute God.
– Cornelius Van Til, A Survey of Christian Epistemology p.10-11
By the deductive method as exercised, e.g., by the Greeks, was meant that one begins his investigations with the assumption of the truth and ultimacy of certain axioms, such as, for example, that of causal relation. The question whether these axioms rest in God or in the universe was in that case not considered to be of great importance. Not as though the question was not raised. Plato did consider the question whether God was back of the ideas or whether the ideas were back of God. Yet this question was not given the importance that we give to it. We must put the point more strongly. The question was, in effect, given the wrong answer. It was assumed that the true, the beautiful and the good rest in themselves, and that God is subordinate to them. For us the question is all-important. If the axioms on which science depends are thought of as resting in the universe, the opposite of the Christian position is in effect maintained. The only rationality they know of in the universe is then the mind of man. Hence the alternative may be stated by saying that according to the Christian position, the basis of human investigation is in God, while for the antitheistic position the basis of human investigation is in man.
Similarly with the more modern method of induction. What is meant by induction as a method of science is the gathering of facts without reference to any axioms, in order to find to what these facts may lead us. Many scientists claim this method to be the method of science. But we have already seen that the usual assumption underlying this method is the antitheistic one, that there may be any kind of fact. Hence the difference between the prevalent method of science and the method of Christianity is not that the former is interested in finding the facts and is ready to follow the facts wherever they may lead, while the latter is not ready to follow the facts. The difference is rather that the former wants to study the facts without God, while the latter wants to study the facts in the light of the revelation God gives of himself in Christ. Thus the antithesis is once more that between those for whom the final center of reference in knowledge lies in man, and those for whom the final center of reference for knowledge lies in God, as this God speaks in Scripture.
Accordingly, we pay scant attention to the historic quarrel between the apostles of deduction and the apostles of induction. Our quarrel is not with either of them in particular but with both of them in general.
– Cornelius Van Til, A Survey of Christian Epistemology p.8-9