Dr Greg Bahnsen - The Place of Logic and Emotion: The Place of Logic in Christian Thinking (Part 1)

This recording has been released into the public domain by the Bonson Institute, where we aim to bring into captivity every thought to the obedience of Christ.

This evening we take up a topic that really defies treatment in the time allotted to us in one presentation. But I'll make an effort, I hope a noble one and perhaps a beneficial one, to do some discussion of the Christian's relationship to the subject of logic. This is a question that is many faceted, one that could take a good deal of time to discuss just in terms of what logic is and the various theories of logic and rules of logic and use of logic, and also the more general subject of argumentation that surrounds the subject of logic, and then the whole notion of the Christian use of reason and reasoning and then where argument takes place in the Bible and what forms of argument are valid forms of argument and which are more persuasive forms of argument. So I mean, we could go on and on and on. Really, this is quite a broad subject. What I'm basically going to do tonight is basically introduce you to what logic is. And then I'm going to give a contextualizing theology of argumentation. That is, I want to say what logic is and then do a theology of logic. And then I want to discuss a few ways in which the Christian wants to see limits to logic. And finally I want to take up the difficult question of Scripture and apparent contradictions, how we deal with what seems to be illogical in the Bible. So first of all, let me begin by talking about what logic itself is. Often enough, when evangelicals discuss the question of logic and they give their own views of the Christians relationship to logic, there's a good deal of ambiguity involved in what the word logic is all about. That's why I think we have to start there in our discussion. Just so you'll know what I'm talking about tonight and toward an understanding of what logic is. Let me begin more broadly with what argumentation is. An argument can be defined as a group of propositions wherein the truth of one of those propositions is asserted on the basis of evidence that is furnished by others of those propositions. Okay, so we have a number of propositions, P, Q, R, S and T. And we're not going to say that the last proposition is the conclusion. I mean, if you read a paragraph plot, sometimes the conclusion is stated in the middle of the paragraph, paragraph, and you have supporting evidence given all around it. So for the sake of what an argument is, in my discussion, it makes no difference where the conclusion appears. The point Is you have an argument when the truth of one proposition is asserted on the basis of evidence provided by others. So what we'll find is a sequence of statements. All but one of these statements will be premises for the point that's being argued for. And that point being argued for is called the conclusion. And that conclusion is thought to follow from the other sentences or the other statements. And so argument tonight does not mean talking to people in a contentious, disagreeing and nasty way. You say he's a very argumentative person. Well, that may be an offshoot of the use of the word here, but here tonight in our discussion, argument is simply the use of some propositions to support another proposition. Notice then that an argument is going to require that some proposition is asserted as following from other propositions. I'm going to assert Q as following from P. Now that is different than a conditional statement. If somebody says if P then Q, he's not giving you an argument, he's giving you a proposition. He says, here's a truth for you. The Q follows from P. But if he says, I assert Q on the basis of P, then he's arguing. Let me illustrate. Here's a conditional statement. If the fetus is a human being, then abortion is murder. That is not an argument. That's a claim. That's a statement. That's a proposition. If P, then Q. If abortion, excuse me. If the fetus is a human being, then abortion is murder. There is no premise here asserted, no inference is made. No conclusion is claimed to be true. It is just hypothetical. If this, then that. Now this is going to seem almost hair splitting to some of you, I'm sure, but in logical theory and philosophy it's very important to draw this distinction. But let me change that. If the fetus is human, then abortion is murder to an argument by the change of just two words. Because the fetus is a human being, abortion is murdered. There. I don't have a hypothetical claim. If this is the case, then this follows. You notice that pro abortionists can agree to the truth that if the fetus is a human being, abortion is murder. Why can they agree with that? Because they think that's very true. If that were the case, abortion would be murder. But it's not the case, so we have no problem with that. But an argument is because the fetus is a human being, abortion is murder. Okay, one more clarification. Not only is an argument more than simply a hypothetical proposition, an argument I've said is an assertion of some proposition on the basis of other ones. An Argument is also different from an explanation. I've said an argument is not simply a proposition. It's the assertion of a proposition on the weight of the evidence provided in others. And now I'm going to say an argument is not simply an explanation. And again, this is the sort of thing that to your garden variety way of reasoning and talking to people doesn't make too big of a point. But it is highly significant that you distinguish between the cause of something and the reason for the truth of something. The word because often signals a causal connection rather than simply offering evidence or grounds or a reason for believing some proposition. And I can give you an example of that. Because Betty forgot to add yeast, the bread did not rise. Because Betty forgot to add yeast, the bread did not rise. Is that an argument? That's not an argument, that's an explanation. The because here is not offering grounds for the truth. It's arguing an explanation for a situation in the world. Somebody doesn't say it is true that the bread did not rise. My argument for the truth that the bread did not rise is that Betty did not add yeast. Well, you can see that would not be an argument at all. Or if it is, it would be a terribly shabby one. The fact of the matter is this may be miracle bread. I mean all sorts of things may have happened. That it is not risen bread or that it's flat does not follow from the fact that no yeast was used. Although it may be an empirical or scientific truth that for us we must use yeast. All I'm getting at here is that the word because often enough shows you that we have an explanation being given rather than an argument being given. An argument says the proposition P is true on the basis of the following other propositions or evidence. That's an argument, not simply a proposition by itself. If this, then that not just an explanation because this than that, but because this is the case, the truth of this other follows that just by way of general introduction to the whole question of argument. Now I also need to, for the sake of tonight's discussion, distinguish between truth and validity. When Christians argue with unbelievers and argue with each other, and when most people, a man in the street argues with another man in the street about just about any subject, you'll often find that when he wants to speak of the truth of his conclusion, he'll speak of the truth. He'll speak of his conclusion being valid. And when he wants to speak of the validity of his argument, he'll often speak of the truth of his argument and In a rough and ready way. We understand people talking that way. But there is a great difference between truth and validity. And I suppose the easiest way to point that out to you is to say that there can be very valid arguments that have false conclusions. I'm now going to give you a valid argument. If the moon is made of green cheese, then the earth is in desperate trouble. The moon is made of green cheese, ergo, therefore we're all in trouble tonight. Well, now, you see, that's valid. If P, then Q. P, therefore Q. That's a valid form. The structure of the argument's right. If P, then Q, P is the case, therefore Q. If the moon is made of green cheese and the earth is in trouble. The moon is made of green cheese, therefore the earth is in trouble. But as it turns out, both of the premises are false premises. And the conclusion is a false premise too. By the way, I could give you false premises in a true conclusion. Okay. I mean, if you get two of the right sorts of falsities working against each other, they will cancel each other out and you'll end up with the truth. So there's a difference between the form of the argument, whether it's valid or not, and the truth of its conclusions and premises, or conclusion and premises. Moreover, a person can have a true conclusion and invalid premises. Somebody argues, if Shakespeare wrote Paradise Lost, then Shakespeare is a great author. Shakespeare wrote Paradise Lost, therefore Shakespeare is a great author. I offer this argument to you, and somebody stands up and says, now wait a minute, that's utterly ridiculous. And you say to the person, you mean you don't think Shakespeare is a great author? No, no. It's not that the argument doesn't come to a true conclusion. It's that it's a very poor argument. It uses invalid premises. So you can have a valid form of argument and a false conclusion. You can have an invalid form of argument and a true conclusion. And so these illustrations are only to help you make. Remember, strictly speaking, we want to distinguish between truth, the truth of a proposition, or the truth of a conclusion and the validity of an argument form. Validity has to do with form, and truth has to do with material content, if you want to take it very easily like that. So we know what an argument is. We know the difference between truth and validity. Let me very quickly run over the kinds of reasoning and the kinds of. Of argumentation that have to be distinguished. We sometimes speak of material reasoning. By that we're talking about arguments, the validity of the arguments, the validity of which arguments depends upon the Actual content of what is being argued. There are some arguments that turn upon what the subject matter is and what you're talking about. These are usually called inductive arguments, arguments from evidence. So a scientist wants to prove that a certain relationship holds between this element and another element. The way he reasons and the kinds of arguments that he uses will often depend upon the content of his claims. Moreover, in such inductive arguments, the conclusion is considered to be rendered probable by the truth of the premises. The conclusion is probable if the premises are true. Over against material reasoning, we have what is called formal reasoning. Now here the important feature of the argument is not the content of the claims, but rather the form of the argument itself. That is, formal reasoning is talking about validity and not simply truth. Then formal reasoning, often called deductive reasoning, is reasoning in which the conclusion of an argument is considered to be a necessary consequence of the truth of the premises. Now, I said a moment ago, in material reasoning, the conclusion is rendered probable if the premises are true, but it's not necessary in formal reasoning, the conclusion is necessary if the premises are true. Let me give you some examples of material reasoning and formal reasoning. Here are some kinds of arguments that are used in material reasoning. There are category revision arguments. Somebody says, well, if we don't have a democracy, then we're going to have a dictatorship. Now that argument, or an argument to that effect may be calculated to change the categories of your thinking, to revise the way in which you organize material for thought. Somebody might want to argue against this form of argument by saying, no, there are other choices between democracies and dictatorships. And therefore they would argue that we need to recategorize our scheme of thought so that we allow for other possibilities. Another form of material reasoning is called the dilemma. Somebody holds to a position and you want to put them on the horns of the dilemma. Which is to say, well, if what you're saying is true, then the following consequent comes from it. But if what you're saying is not true, then this other consequent comes from it. And as it turns out, you can't live with either one of those consequences. And so you've got a dilemma. Or if what you're saying means A, then B is going to follow. And if what you're saying means C, then D is going to follow, but you can't live with B or D, and therefore all the interpretations of the premise that you're offering us are troublesome to you. That's a dilemma form of argument. Then there's also the Reduct you ad absurdum form of argumentation, you take something. Well, if that's true, then the following comes from it. We can conclude that and it turns out that what you did is not at all acceptable to the person. Reductio ad absurdum, showing that his premise or his argument reduces to absurdity, reduces to absurdity in the sense that he can't accept the consequence of what he's falling for. Then there are arguments from analogy as well, arguing that from the similar features, one or two or three similar features of something, we can deduce or infer a fourth similar feature, although that is not one for which we have direct evidence. Then there are all four tory forms of argumentation and material reasoning reasoning from the lesser to the greater. Well, if this is true in this case, then how much more would it be true in the following? I don't have time to give you a course in logic and argument and illustrate all of this, but that's what we're getting at when we talk about material reasoning. Now, corresponding to the good forms of such argumentation and material reasoning, there are also what are called informal fallacies of reasoning. We have fallacies of relevance, fallacies of ambiguity, fallacies of presumption. For instance, a fallacy of relevance is an illustration would be an ad hominem argument argument against the man himself. Somebody says, well now what Ted Kennedy said about this or that proposal can't be true because after all, that man has an irresponsible life with respect to his family. Well, it may or it may not be true that this moral evaluation of the man is the case. But of course, whether he does or does not support his family and live in a way that is pleasing to us has nothing to do with the truth of what he's claiming about, say, an oil embargo or the sins of the Shah of Iran or what have you. That's an ad hominem argument arguing against the man rather than against his argument. That's weighing the argument on the basis of the speaker rather than on the merits of what is spoken. By the way, that's also one of the most common fallacies found in the Christian Church. We often decide what we will believe in theology on the basis of who says it and whether we like or dislike the person rather than on the basis of the merits of the argument proposed. Another argument or fallacy of relevance is the appeal to the mob, as we call it. So here you have a politician who is reasoning with the crowd and the way he gets them to agree with his conclusion is he appeals to the instinct in the mob that they want something. Okay, so this is true because you're going to like it. We often enough see that the appeal to the mob, the appeal to the majority, the appeal to, well, if, you know, 15 million Americans have bought such and such a product, then it can't be all wrong. That's an appeal to the mob, an appeal to, you know, the masses. Another kind of fallacy that we run into is not the fallacies of relevance, like ad hominem or appeal to the mob, but fallacies of ambiguity so that a person reasons in a way that equivocates in certain key terms of his argument. Okay, I'll give you a rather obvious case of equivocation. Some dogs have spots. My dog has spots. Therefore, my dog is some dog. Obviously, we're using the word some here in two different ways. One in a quantitative way. That is a quantitative way. Some dogs have spots. And then the conclusion, my dog is some dog in the sense that, wow, this is really a great dog. Qualitative use of the word. And then there are fallacies of ambiguity arising from what we call reification, treating some general notion as though it were a concrete subject. Reify means to give it substance, to substantize something. Okay, so you have arguments from nature. You often hear from people you know, nature has the following qualities. And then we argue from the qualities of nature. But of course, nature is nothing more than a generalization for certain things. And therefore, to start talking about nature as though nature were a person. You can't fool Mother Nature. And that sort of thing is to reify what is really a generalization or an expression meant to summarize something. Okay, that's a fallacy of ambiguity. Another kind of informal fallacy is a fallacy of presumption, like the hasty generalization. Here's a hasty generalization for you. My congressman. My congressman has been disciplined by the House Ethics Committee, and therefore all congressmen are unethical. That's a hasty generalization. It's taking one hopefully unique or extraordinary piece of evidence and making it cover the whole field, when in fact it doesn't. Another kind of fallacy of presumption is what we call complex question, the famous have you stopped beating your wife? And the reason that's a fallacy of presumption is that it presumes you can answer one issue and force the man to answer the second, when in fact it's an open question on both. One, has he ever been beating his wife? And then, secondly, has he stopped? That's a fallacy of presumption. The complex question or the fallacy of false cause. I'm going to tell you what all, by the way, this fallacy of false cause appears often enough in theological literature and in Reformed literature, and might I say with, I hope, a due sense of humility in an attempt to improve all of our efforts, often enough in our own literature. The fallacy of false cause says, because A preceded B, A is the cause of B. I'm going to tell you what all the problems in our country stem from. I'll tell you. It's the New Deal. How do you know that? Well, because the New Deal came a few years ago and obviously we got these problems today because it flowed from the New Deal, right? No, it doesn't follow at all. I mean, that's like saying nighttime produces day because day follows night. That's the fallacy of false cause. The fact that something follows in time does not mean that it is the cause of or has been caused by or that there is some connection in that way. So those are various kinds of fallacies, fallacies of relevance, fallacies of ambiguity, fallacies of presumption. Now, let me turn from material reasoning to talk just for a moment or two about formal reasoning, deductive reasoning, where the conclusion is supposed to be necessarily implied by the premises. This is the realm that is usually called formal logic. Formal reasoning has different kinds of arguments to be countenanced as well. We have categorical reasoning, that is class reasoning, having to do with the membership in classes or set. So here's a categorical form of reasoning. This is the set of sailors. All sailors are drunkards. Okay? That's the first premise. Okay? Now, the set of drunkards work for falls within the set of sailors. Or let's do it the other way around, set of drunkards. The set of sailors is going to fall within the set of drunkards. If it's true that all sailors are drunkards, then you'll never find the sailor, the top part of the set of drunkards. And now somebody says, and all men are sailors. Okay? So the class of men category of men falls entirely within the domain of sailors. You'll never find a man that's outside of the circle of sailors, what's the conclusion? All men are drunkards. Okay? If all sailors are drunkards and all men are sailors, and consequently all men are druffets. Now that is an illustration of categorical reasoning or class or set reasoning. And then there's also propositional formal reasoning, I.e. reasoning with sentences rather than classes of people. You take sentences or propositions. So somebody says if P then Q, therefore P, therefore Q. Now, P and Q have got to stand for sentences here. It won't do any good to put classes here. Okay, if men, then sailors. Men, sailors. I mean, it's just ungrammatical, Obviously. What's got to fill these place markers, if you will, are sentences or propositions. Okay, if Socrates is a man, therefore Socrates is mortal. Socrates is a man, therefore Socrates is moral. If P, then Q. P, therefore Q. That's called propositional reasoning. And let me give you a couple of our three common forms of reasoning. You probably use them without being aware of it all the time. This here is called a hypothetical argument. Okay, from the if then form. If, if, then you affirm the antecedent. Conclude with the consequence. Now there is a form of hypothetical reasoning. This is called modus ponens. And modus ponens is in some senses the reversal of that. If P is in Q, not Q, therefore not P. That's also a valid form of argument and that is a valid argument. Because every substitution instant will be a valid argument. The form of this argument is always going to be valid. No matter what you fill into P and Q, the form is always going to work out. If this is January 1st, then Christmas is past. Christmas is not past, therefore this is not January 1st. Okay, if P, then Q, but not Q, therefore not P. Once you buy the truth of this connection P then Q. Then by asserting P, you must also assert Q. And by denying Q, you must also deny P. Please note that you can't turn these around or you're going to get common fallacy. Somebody says if P then Q and then says Q, therefore P. That's the fallacy of affirming the consequent antecedent. Consequent, affirm the consequent affirming antecedent. That's not a valid form of argument. Nor is this a valid form of argument. If P is in Q, If P, then Q, not P, therefore not Q doesn't follow at all. It may be that Q is true for other reasons altogether other than P. And so the denial of P does not mean you have to deny Q. So once you buy if P then Q, and you affirm P, you must affirm Q. If you deny Q, you must deny P. But all the rest you see is open, except for grabs. Those are that's modus ponens and modus tollens. In formal reasoning, then symbolic logic gets into the use of Truth functional connectives and quantified symbolic logic enables you to quantify over truth functional connectives so that you can have arguments that are very complex. There exists an X such that for all X's. If P is an X, then if X is a P, then X is a Q. Now, I'm not even going to bother to try to explain that to you, but what you have here are quantifiers. It's not just talking about the relationship of qualities or the relationship of categories or the relationship of propositions, but it's also quantifying over the subjects discussed in the various propositions. There is an X such that I should have for all Y. If X is a P, then Y is a Q. That tells you that this relationship right here is true only for one particular or some particular X's, not all X's, but it's true for all Y's. For all Y's, it is the truth that there exists an X such that this relationship holds. Now you can reverse that too. You can have, well, for all X's and for all Y's, it is the case that. And then you draw a relationship between them. Or you can say there is some X and there is some Y such that. That's quantified symbolic logic. And obviously you want to go to school a few years before you get into that because you have to build a rotation. Heard that sort of thing. Okay, I've talked about material reasoning, I've talked about formal reasoning and one more form of reasoning that I'll mention tonight, adductive reasoning, where a person brings an organizing model to bear on diverse data. Okay, here's all this information out here, and I want to organize it somehow. And my argument is if we use the following model, say the Newtonian view of science or, or the Einsteinian view of science, or if you will, the Calvinistic view of theology or the Thomistic view of theology. These are models that hopefully will organize the data that we find in the world or the data we find in the Bible and so forth. That is not strictly material reasoning or formal reasoning. That is called adductive reasoning. It's taking a model and seeing if it doesn't help organize all the. The data that we have to deal with. We're taking a while getting there. We're still in the introduction. We want to know what is logic? So that we can answer the question what's the relationship with a Christian? For logic, we begin by telling what an argument is and distinguish truth and validity in argumentation. And then we talked about the various kinds of reasoning. That's what we've been doing for the last few minutes. We have material, formal and abductive kinds of reasoning. And now finally, after that lengthy explanation in that context, let me tell you what logic is. Logic is simply the study of sound argumentation, the study of the methods and principles used in distinguishing correct from incorrect reasoning. We've been talking about arguments and kinds of arguments or kinds of reasoning. Logic is argumentation about arguments. Logic, I'm saying, is a second order kind of discipline. Here you have scientists arguing inductively or deductively about some subject matter. But then somebody comes along and says, now what are the good kinds of arguments? Somebody else says, well, I don't agree with the choose think of the good forms of arguments. And as they argue with each other about arguments, they're having an argument about the best kind of arguments. They're doing logic. I think that's the simplest way I can put it to you. It's a second order discipline. It's the study of sound arguments or it's argumentation about arguments. That's why we call it meta argumentation. It stands behind and explains argumentation, its arguments about arguments. Logic is concerned with facts about a specific discipline, and the specific discipline is the discipline of arguing. Logic employs arguments about the way we ought to argue. And so the laws of logic will turn out to be what, what are the laws of logic? If logic is arguments about argument, the laws of logic are the rules governing the use of arguments. So the next time somebody says to you, well, that argument that isn't logical, you say, okay, well now what rule of argumentation is it that you think has been broken here? Because logic has to do. The laws of logic have to do with the rules governing the use of arguments. Now what does this say about logic itself? I'm going to move on now from my introduction to logic as meta argumentation. Arguments about arguments. Logic explores all the arguments you see, you run into and tries to analyze whether they're good or bad one. That's logic. Now we want to get into a theology of logic. If somebody is using logic, I think we have to point out to that person that that presupposes a certain kind of world. Doesn't presupposes a world where arguments are possible. Well, that's not very significant. Of course it presupposes that you can have arguments if you can have rules of logic. Yes, but now you see the unbeliever. It may just turn out that the unbeliever has a view of the world where arguments in the long run aren't possible at all. It may be that this world of sound and fury signifying nothing, that we're all nothing more than the objects that have been produced out of the womb of chance. And that surrounding us is not light and intelligence and purpose and plan and reason and all the rest, the mind of God, but rather what is surrounding us is deep, dark ignorance and mystery, incoherence, absurdity. The existentialist says we live in an absurd universe. The meaning that you find is the meaning you create in such a universe. If that's really the way the world is, Are arguments possible or are they not just, again, sound and fury signifying nothing? Well, if they are, then of course there's no sense to logic. Logic presupposes I'm pointing out a world where arguments are possible. Logic is not. It's going to be a little difficult. Hold on. Logic is not metaphysical. Logic is not talking about the structure or machinery of the universe, if you will. See, it's not as though if you study the world, you find out in the world process history or science or cosmology or what have you, that you're going to find out there are certain basic laws built into the structure of reality. That isn't what logic is. I mean, reality may be structured a lot of different ways, but logic has to do with the way we think and reason. Logic is not the universe's machinery. However, logic does require a certain metaphysical context. I've said, first of all, logic is not metaphysical. Logic is not talking about what is the most real structure of the world, if you will. But logic does require a certain structure of the world. Logic is a kind of argument. And the Christian says, therefore it's a gift of God to be used by God's creature to subdue the earth. The use of logic is part and parcel of the image of God. Because God thinks in a certain way, we are to think his thoughts after him. We are to reason as God would have us to reason. Human logic is to be a reflection of God's knowledge of the relationships holding between the truths of the universe, not the relationships holding between the various elements of the universe. Where the relationship of Venus to the Earth is not a matter of logic, it's a matter of astronomy. But there is a certain relationship between certain truths about Venus and certain truths about the Earth. And that relationship, which reflects the knowledge of God's mind, is one that we are to toe to when we reason. And so human logic is a reflection of God's knowledge of the relations holding between the truths of the universe. God does not perceive different relationships between truths than we do. The objects of our thought and the objects of his thought are identical. However, man perceives those relationships in a way that is different than the way God perceives him. Man perceives logical relations as a creature, while the thought of God. God's thinking causes things to be the way that they are causes them to be the case. We do not think in that way. We rather receive the truth. God creates the truth and we receive it. God perceives everything exhaustively. We perceive things only partially. And that's why progression in our learning takes place. That's why it may be that certain paradoxes may be inevitable in virtue of our own creaturely nature. Whereas paradoxes aren't necessary and inevitable in God's thought. And there is no contradiction in God's thought. Now. Before the fall of Adam into sin, Adam was given verbal revelation by God. God told Adam certain things, how Adam was to behave, what Adam was to think, and so forth. He was given propositional knowledge. Then there were propositions he was supposed to believe. Paul tells us in Romans 2 that that propositional knowledge is in some measure still held by all those who have a created status. All human beings, in virtue of creation, know certain propositions about God and how they are to behave. And so creation itself creates the situation where man has the ability and actually possesses propositional knowledge. And as the image of God, man has a knowledge of the truth. He knows that God is the Lord. He knows that the law of the Lord is his requirement. So the image of God also shows that man has the ability to argue and to reason. The cultural mandate shows that man has the responsibility to reason. Because man is to name the animals, he's to subdue the earth. And that means he's to extend the propositional knowledge that God has given him. The names of the animals could not be deduced from the prohibition of eating the tree. From the tree the knowledge of good and evil. That is, Adam couldn't sit down in his armchair and say, now let me see. God has told me such and such propositionally. And from that I can deduce that this thing is to be called a lion, and that thing is to be called a camel, so forth and so on. Rather, Adam had to do a certain kind of study of the world. Adam had to name things in terms of their characteristics. He had to understand them. And that meant he had to extend his knowledge. But to extend knowledge, that meant that Adam had to argue. Remember, argument here is Very broadly, the truth of one proposition is asserted on the basis of the truth of other propositions. So from the evidence available to him, Adam would then draw certain conclusions. It turns out then that because of creation, man has the ability to reason, and because of the cultural mandate, man has the responsibility to reason. And the way that man is to reason is by thinking God's thoughts after him. He is supposed to understand the world as God would have him understand it. He is to conform to the norms found in the word of God, and he is to think God's thoughts after him. Now, as man before the Fall would have reasoned, it's important to see that there would have been a difference between context in which he had an open mind, subject only to the restraint of God's word, in context in which he was not to have an open mind at all. For instance, Adam had an open mind when it came to discovering things about the world and applying God's word to the world. He had to have an open mind about camels and lions being different. However, when it came to naming these things, Adam didn't have an open mind in the sense that he could name them just anything. He couldn't name them God, for instance. That would have been a violation of God's revelation to him. And so Adam did have an open mind, and in that case, naming the animals, God's revelation was a restraint upon his reasoning. On the other hand, when it came to what God required of him, the law of God, or when it came to the character of God himself, that God is the Lord and his Godhead, his divinity, in such matters as these, Adam could only reason in a circular way. He could only reason. This is true because God has shown that it is true. His mind wasn't to be an open mind there because these were unchallengeable propositions. Adam was simply to submit to the revealed presuppositions, the worldview that God provided for him. Now, that's just an elementary look at reasoning before the Fall. What does the Fall now do to man's reasoning? Well, after the Fall, the unbeliever has not lost information. It's important to see that the fall of man was not metaphysical. It didn't change humanity. As humanity after the Fall, men didn't cease to have noses. If I can put it that way. Unfallen man and fallen men both have noses. Moreover, the tools that Adam would have used to dig in the earth before the Fall and after the fall would be the same sorts of things. A spade would work in both places. Now, We've already said that logic is a kind of tool. It's an argument about arguments. Consequently, the laws of logic before the fall and after the fall remain the same. There has not been a change in the laws of logic. The laws of logic are unchanged. Now, of course, sin does affect man's ability to use the laws, doesn't it? In one sense it affects his abilities because, well, men become perverse and lazy and confused. They don't have the proper motivations and that sort of thing. But then, of course, the laws of logic are used differently by fallen men than by unfallen men. The laws of logic, the tools, are going to be put to a different use. Now, Dr. Van Til illustrates this in terms of a buzz saw. You have a buzz saw that can cut against the grain or it can cut with the grain. The buzz saw is still a buzz saw. The tool is still the tool. But it makes all the difference in the world whether you put it to a good or to a bad purpose, whether you try to cut with or against the grain. Now, before the fall, man had the same loss of logic as after the fall, and he would have used them with the grain, that is, in terms of the revelation God had given him. After the fall, men use logic how to fight against the revelation of God. It's not that the laws of logic are wrong. It's the use to which they are putting the laws of logic that is wrong. So men still know God after the fall, and they still reason after the fall, but now they reason immorally. They use the laws of logic improperly. They use the laws of logic, if you will, as an ultimate standard by which they can judge God rather than a tool under God so that they can serve him better. Now that's what is true of the unbeliever. The believer has the same laws of logic. However, we must remember that the believer still misuses the truth. We have a tendency not to understand things properly, not to argue properly. So we misuse the truth even though we're believers. And in fact, now our arguments as believers, unlike unfallen Adam, sometimes our arguments must be applied to our presuppositions. Man doesn't stop being a rational being, but now he is a disobedient rational being. He doesn't become irrational, he becomes disobedient by the fall. The difference before and after the fall, then, is the way in which logic is being used, the purpose to which it is being put. And the difference between the believer and the unbeliever in principle is also the difference between the use to which they put logic. The unbeliever uses it as a final standard to judge God. The believer uses logic as a standard under the revelation of God to understand and apply God's truth. The unbeliever uses it as a tool for disproving God and ridiculing the Bible. The believer uses it as a tool for proclaiming the Bible and disproving the unbeliever. So the tool is unchanged. It's only the use that has become unethical. So does logic provide a neutral common ground between the believer and the unbeliever? That's the rub of the question in Christian apologetics. Well, it is not a neutral arbitrator of truth, is it? It's not neutral because just like a buzz saw, it can be set against the grain or it can be set to cut with the grain. It's all a matter of how one is using the laws of logic. So it's not a neutral common ground between the believer and the unbeliever, but it is an indispensable tool in the cultural mandate and an indispensable tool in our understanding of the Bible. And it can be a valuable tool in showing the unbeliever the inadequacy of his system of thought. It may be helpful here to give you something of a biblical justification for reasoning very quickly. It's not systematic, but I think it will help you to see how the Bible requires us to be logical. And I think, although there are many ways to approach this, the verse that I think really sticks out in my mind is Isaiah 1:18. Come now, says the Lord, Let us reason together. Let us reason together. That tells us a couple of things. One, God expects us to reason not just on this subject, but on others. But it also tells us that God reasons. And how are we to reason? We're to reason the way he reasons. We're to think his thoughts after Him. God says, come, let us reason together. And Notice in Hebrews 6:18 that God it's impossible for God to lie. In 2 Corinthians 1:18 and in Matthew 5:37, we see that our yes is to be yes and our no is no. Our word is not to be yes and no. That is we're not to contradict ourselves. God is consistent. He cannot lie. He doesn't say ay and then say not a. That would be a lie, wouldn't it? And we are to be consistent. And God tells us that he wants us to reason with Him. Well, let's put all this Together, God reasons. We're to reason like God reasons, and God is consistent, and we are expected to be consistent. Consequently, we are expected to be logical. Moreover, we are to properly use evidence, and we are to properly reason. In Mark the second chapter, verses six to eight, you see that Jesus, after healing a man, or after saying to a man that his sins be forgiven, is criticized by the Jewish critics of the day. And he says, why do you reason thus in your mind? You apparently don't know how to reason through this. He says, now which is more difficult, to forgive a man's sins or to heal him? And so that you'll be properly convinced that I am the Lord. He says, now rise up and walk. Jesus says, you haven't reasoned properly. If I forgave this man's sins, obviously I'm the Lord and I could heal him as well. In Matthew 16:2,3, Jesus criticizes his hearers because he says, you know, you look at the sky in the morning and the evening, you know what to expect weather wise. But when it comes to reasoning about the signs of the times, you completely failed. So God expects us to use evidence properly and to reason in our hearts in the correct way. He expects us to be consistent in our reasoning. And the Bible tells us there's a need for disputation, for argumentation, for logic and reasoning. In Acts 17:17, we read that Paul was disputing with the philosophers, and in Acts 19:8,9, in the school of Tyrannus, Paul reasoned for many weeks with those who would come to hear him. In 1 Peter 3:15 we are to have a reason for the hope that is in us, a rational account of it, if you will. In 2 Corinthians 10:5, we are supposed to pull down all reasoning that exalts itself against the knowledge of God. Consequently, we not only see that God reasons and expects us to reason and to be consistent and to use our reasoning and evidence properly, but there is a need for and a call for disputation, thinking and argumentation. And then the Bible also, it seems to me, exemplifies reasoning. In Mark 2, verse 28, Jesus says, the Sabbath was not made for man, and therefore what son of man is Lord of the Sabbath? Jesus says, therefore it follows from the premises I've just given you that I'm the Lord of the Sabbath. That's why I can do what I want to on the Sabbath. By the way, in Romans 4:2 and Romans 5:15 and 1 Corinthians 15, verses 13 and following and many more passages, you find Paul using Hypothetical forms of argument. If this, then that. If this, then that. So the Bible over and over it seems to me exemplifies the use of logic and reasoning. It calls us to use logic and reasoning and tells us that in doing so we are reasoning after the pattern of God himself. We ought to reason after the pattern of God himself. Now, I don't want to keep you unduly long tonight. I unfortunately over prepared and brought a bit more than was necessary. Maybe we'll come back to this some other night. I'm just going to summarize. Following 15 pages manuscript. That's the one nice thing of learning how to outline your talks because when you see the clock is getting a little long, you know, just sort of lop it off, you know. This one whole segment goes the limits of logic. Now this was by way of introduction what is logic? And I only gave you a smattering and a taste there, I realized, but tried to get you some idea of what we're doing when we use logic. Then by this theology of logic I wanted to show the relationship of our reasoning to God's reasoning. Our relationship, the relationship of our reasoning to the unbelievers reasoning, the question of common ground. And in a sense this has all been positive. I'm saying we must be logical. The Bible wants us to be logical. But now I'm going to go the other way. I'm going to say let's not make logic an idol. After all, there are certain limits to this good tool that God has given us to use. The ways in which I was going to try to show you the limits of logic were these in the first place. Despite all of the magnanimous claims made for logic by many evangelical apologists today and many theologians and certainly by many unbelievers, the fact of the matter is there is no agreed upon science of logic. The state of the theory of logic today in the academic disciplines is deplorable. That isn't to say that the rules of logic from teacher to teacher difference. But if you want to demonstrate to somebody how bad off the science of logic is, just ask two questions of anybody that thinks they know something about logic. Ask them what is the agreed upon status of the objects of logical rules? I mean, when I give you, here's a rule of logic, if P, then Q P therefore Q. Now what am I talking about when I go through this? What is this all about right here? Somebody says, well, it's about marks on a blackboard. Oh, you're laughing. You see, materialists believe that don't they? It would have to be something material because there aren't any immaterial realities, so it can't be thoughts we're talking about here. So there are people who say, well, it's really the electrical connections within somebody's brain. That is to say, logic reduces psychology, materialistic psychology. Some people would say, well, it's really the conventions of language. This is the way we decide and stipulate to use our language. Now they say, no, there are abstract entities, certain rules of logic, rules of consistency. And so what is it that logicians talk about? Do they talk about thoughts? Do they talk about electrical, chemical relations? They talk about psychological processes. What is the subject matter of logic? Moreover, what is the kind of evidence that logicians are supposed to bring to support their rules of logic? Well, the kind of evidence that is relevant will depend upon the metaphysical status, the kind of reality that you're talking about. And consequently, because there's no agreement in terms of the theory of reality among logicians today, the state of the theory of logic is deplorable and just in disarray, as a matter of fact. And I brought plenty of quotations and illustrations to that fact that I won't go through. Now, there's also the unsettled character of the study of logic to be taken into account. What is a logical rule? What kind of evidence can be brought to bear in favor of a logical rule? And then thirdly, we can ask, how is it that logical rules are necessary? Why should they be seen as necessary? Somebody says, well, look, here's my argument for this logical rule. I'm going to illustrate two ways you can go on this. I'm going to give you a logical argument for this deductive argument. Why should you accept this? Why should you accept the rule that if P, then Q, P, therefore Q. He says, for the following reason. Now, I'm going to illustrate this schematically because there's no way possible I can teach you to understand the philosophy of logic from that which is far as it sounds, right, Maybe presumption, even I understand, so I'm not going to even attempt it. Let's say whenever it fills the black box. That's the very complicated scholarly, technical argument in favor of this law of logic. So the person says, now all this that I'm saying is true, it follows that modus ponens is true. Now, all of this is true. Therefore modus ponens is true. What's the problem? By using modus ponens to argue, he has begged the question that is he has presumed the very thing he's supposed. But now, after all, what if he does the opposite? What if he doesn't make some kind of logical argument, but uses an inductive or empirical or scientific argument, an argument like this. Most times that scientists use this kind of reasoning pattern, they are able to accomplish their purposes. Now, can he assure us that every time we use it, it's going to accomplish our purposes? No, in fact, he can't even assure us that every time it's been used, it's been used and it's been successful, because he can't in any way examine every argument that's ever been used. So it turns out if he doesn't try to give us a logical argument proving it, all they can give us is an inductive argument. And what that tells us is that, well, very probable if P, then Q. P, therefore Q, very probable. But you see, that doesn't justify the law as a logical law. This tells us that's a kind of rule of science, a rule of thumb. It should be used, and very likely it's going to follow. So it turns out that the necessity of logical laws cannot be explained by an unbeliever. He cannot tell you the status of logical laws. He can't tell you what we're talking about. Propositions. We're talking about reasoning in the mind, psychological material, electrical, chemical, what is it we're talking about? Can't tell you the nature of the evidence he uses. And it turns out he can only reason in a circular fashion in trying to justify his laws. Moreover, the laws of logic have a limited use because, as a matter of fact, they are purely formal. Purely formal. It's really neat. You see, you're talking about logic when you got P's and Q's and S's and T's and R's and all the rest. But what happens when you want to apply it to some natural language like English or French or German? Which is to say, what happens when you want to apply it to your life? Well, let me tell you what happens then. The nice, neat, certain package of logic turns out to be very trivial, not very helpful. Here's a standard law of logic. A is A. It's called the law of identity. I used to have an English professor who ridiculed my escaping philosophy to say, you know, those philosophers, they came up with such dramatic things as A is A. And they think they've accomplished something. We in literature. But he's talking about human, you know, things of human interest and all that sort of Thing. Well, for all of that kind of ridicule, A is A is a very important law because that also means that A is not not a. A is not not a. That is to say that something either is or is not a. These are A or not a, called the law excluded minimum A. In between those two, three basic laws of flaw. Without them, one couldn't reason be consistent. Okay, that all looks very good. We've accomplished something here. A is A. What happens when we try using this in a natural language? Obviously, if this is a logical law, and this is a logical law, anytime somebody denies a sentence of the form A is A. To deny, to negate a sentence of that form is to be illogical. One would think, denied this most elementary law of thought. Well, I'm working for somebody. Seems to have an unethical crap in this business. And I go in and I say, you know, you know, it's cheating, you know, to take the inventory in what you're doing. That's just not true. I said, now what, Sonny? Go along the way and do what you were told to do, because business is business, okay? Business is business. A is A. Here I am, as a Christian saying, no, wait a minute. Business is not business. Would it make sense for the guy to respond? Wouldn't you be a logical little creep? You can't reason like that. Business is business. Don't you know the most elementary law of logic? Well, it would be totally ingenious and inappropriate for the man to argue that way because what is going on? He's using business in two different sets. The way I run my business is my own business, okay? And so it turns out that the only way you can use these formal laws of logic is if you find some way to translate them into a natural language. One has got to be able to use his senses and his comprehension and his understanding of semantics and the world before he can start using the laws of logs. They are so formal that they are absolutely no use to us until we can find ways of taking a natural language like English and applying it to the formal laws of logic. So there are definitely limits to logic. There are arguments among logicians about the laws of logic, the structure of logic, the status, the necessity, and all the rest. And there is development in the science of logic from the time of Aristotle down to the time of Bertrand Russell. There were arguments and there was development. Since the time of Russell, Bertram Russell, there have been even further arguments in development in the science of logic. And I had a good deal of stuff to tell you about that But I'm going to skip it and I hope you just take my word for it. The fact is that logic is a developing science. We're learning more and more how to argue about arguments is what that amounts to. So that then finally brings me to the final question and probably the one that motivates your desire to have me speak on this subject tonight, I would imagine. And that is? Well then, what do we do? How do we use logic when it comes to the Bible? I told you what logic is. I've given you a theology of logic of sorts. I've talked about the limits of logic. I've said you've got to use logic, but on the other hand, remember its limits. And now we come to the question, what about apparent contradictions in the Bible? The unbeliever looks at these and says, aha, violations of the laws of logic right here in the Bible. So the Bible can't be true, therefore it can't be the word of God, if there is a God at all. Well, the believer does want to admit that we have apparent contradictions in Scripture. Apparent contradictions in Scripture, the Trinity, predestination and human responsibility, the idea of glorifying an all glorious God in history, all of these appear to be contradictory. How can it be that that something is both three and one, that somebody does have responsibility, which is to say he can choose what he's going to do, but in fact the choice has already been made. How is it that a God that can receive no glory because he's got all glory already, nevertheless receives glory through our actions in history? I mean, how can these things be the case? Apparent contradictions? Well, the believer wants to say that these things are not unreasonable. They are beyond our reason. They are beyond our reason, but not contrary to our reason. It is just the case that logic is not an appropriate tool for some issues. The reason it is not an appropriate tool is because we don't have the category scheme necessary in the understanding of the full subject matter in question so that we can understand the proper relationship of concepts. That is to say, if I knew how God predetermined everything and nevertheless left me responsible for the decisions I made, then I might be able to understand the logical relations of these two concepts. But because I don't have that kind of knowledge, I'm not in a position to judge the logic of the matter. The validity of logical laws derives from God's character. God cannot deny himself. He can't do things contrary to his nature, his purposes, to his promises. And so the validity of Logical laws derives from God's own character. And there's a kind of interconnectedness within the creation. All those things which are true and can be known about creation are interconnected according to the mind and the plan of God. And yet our knowledge of these things is limited. We don't know everything about creation. We don't know everything about the world. And so you see, our knowledge of the world must be balanced by our thinking God's thoughts after him. We must conform to God's way of thinking, since he knows all of the exhaustive relationships of things and we only know a few of them. God is the only one who determines what is ultimately possible. We're not the ones who can say what is and is not possible, logically speaking. Now, unbelievers, of course, have a false view of the foundations of logic. While observing the same laws of formal logic using the same laws, they will disagree with the believer on the basis of those laws, and therefore their way of using the laws is going to be different than ours. They'll assume that those laws are not founded in the character of God and as such can be used to judge the purported revelation of God. Because we believe God is the foundation of logic and the determiner of what is ultimately possible, we can say in some areas we simply have to say that this is logically possible because God says it's logically possible. And my limited knowledge does not put me in a position to tell you how that is so or to judge that it cannot be so. By the way, your limited knowledge, in addition to your sinful rebellion against God, makes it impossible for you to use logic, by the way, which has no foundation for you as an unbeliever, makes it impossible for you to use logic to judge what God says is and is not logically possible. Scripture, therefore, should control our use of and application of logic. And consistency cannot be purchased at the price of infidelity to the very foundations of consistency. And that's the character of God. Well, why is it that logic breaks down in such cases of apparent contradiction in The Bible, Isaiah 55, 8, 9 tells us that God's thoughts are above our thoughts, that his mind and understanding transcends ours. Now, logic is a part of, it's an aspect of thinking, it's arguments about arguments. And it may very well be that God, because his knowledge is above and beyond our understanding, is able to use a different kind of logic and knows more about arguments about arguments than we do. And finally, we want to add this something we've already observed. Logic Remember, for human beings is a developing science. I think that would have been true even if men hadn't fallen. By the way, Adam would have learned more and more about logic as he subdued the creation. But you see, since Aristotle forward, logic has seen modifications, changes, developments and all the rest and perhaps an improved future. Logic, as we learn more and more through the ages about how to argue, will clear up what appear to be problems in the Bible. There are apparent contradictions in the Bible, but that isn't to say that they are real contradictions. The believer says that the unbeliever can't judge those apparent contradictions because he has no foundation for logic. And it turns out because God's mind surpasses ours and he knows more than we do, that things can indeed be possible that we don't yet understand the logical possibility of. And therefore these things surpass our reason and our logic, but they do not violate our reason and our logic. 1 P.S. how do you know then how far to push your logic? When do you stop pushing for consistency and say what we have here is just we don't know enough? When do you press for a resolution of an apparent contradiction? When do you press for a conclusion to the matter? Well, I think the answer for the Christian is very easy really. When our inferences and our logical arguments would contradict the clear statements of Scripture. It's time that we say stop. God is logical, yet at times transcends our logic. God is consistent with Himself. We can trust that the passages of Scripture that we're dealing with are going to be consistent with themselves. Therefore we should never contradict those statements of Scripture and we should use our laws of logic to understand them and apply them. We should never contradict them. But we aren't to push our logic so far as to say that the Bible itself has made a mistake or that God has become inconsistent because after all, we must finally worship him as our Lord, as our Savior and submit our thoughts to his thoughts. When God says come, let us reason together. Remember that God doesn't say come because I need your counsel. Yes, you would say down the Trinity or things like that. The Trinity or predestination versus responsibility and things like that are cancelled. Saying that people can formulate the doctrines in such a way that they appear to be contradictory. Yeah, I'm not yet convinced that there is an illogical way of stating the Trinity or the, you know, responsibility and God's predestination.

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