Dr Greg Bahnsen - Introduction to Apologetics: Methods VIII (Part 18)

Other people nodding because I've had so many already, I'm kind of worn out. But I suppose, though, we should have a short lesson. I will give more time for questions on the sermon today, which after all, is on the theme of our apologetics class. And so that's not all that inappropriate, but let's begin with the word of prayer. Our Heavenly Father, we are grateful to you that you are gracious and forgiving and that you allow us to come into your presence though we are stained by sin. We thank you that the blood of your son Jesus Christ does wash us clean and gives us a right standing and amazingly can even give us confidence as we stand before you. Because we stand in the righteousness of Christ our Savior. We ask that you would receive us as your people and bless us with enlightenment during this time of continuing education, that you would open our eyes to the scriptures and to their application. We pray that you would improve our lives and help us to witness more effectively for your because of our time together. For we pray in Jesus name. Amen. Because I have determined to extend our seminar on apologetics for another three months, I have a little more time to give illustrations and to deal with common problems. I mentioned this to you last week, and today what I'm going to do is finish out common problems that you can use for dealing with the unbeliever's worldview that probably wasn't expressed real clearly, but that is enigmas and dilemmas and contradictions within the worldview of unbelief that you can exploit as you're trying to defend the faith, to show that those who are unbelievers really are opposing themselves by their unbelief. And then, Lord willing, next Lord's day, I'd like to begin to deal with how to talk to false religionists, that is, those who are not as crass as the atheist, naturalist or materialist that we've been dealing with. They're a little bit easier, in a sense, because they leave themselves wide open to a lot of philosophical problems. But the false religionist says, oh well, I know how to answer that problem the same way that you do. You've got your religion, I have mine. And so now how do we deal with that situation? I'm going to begin at least two or three weeks talking about that. And then what I'd like to do is to take up common problems that the unbeliever will throw at you, like if there's a God, why is there evil in this world? Or something like that. So we're going to continue this for some time, but I will not be able to finish all of that by the end of this three month term in Sunday school. And so what that means is that many of you are going to have to make the commitment to start coming out Thursday night or else you will not. That's right, or else you will not hear the end of the class and all those questions will never be answered. Well, no, not never be answered, but if you would like to get them answered in this class, I'll be continuing on Thursday night. But now look, if you're going to commit to coming out Thursday night so that you can finish hearing the rest of the apologetic series, then you might as well get in the habit of doing that this week because you'll get the benefit of catching up with Pastor Curto's excellent study on the Book of James, which is real helpful for your lives. And so I'd like to see this entire class, maybe one or two might not be there, but almost all of you out Thursday night at Bible study. So if you're at Bible study and Sunday school, the fact that we're switching in a couple weeks won't make any difference to you. All right, enough. Advertisement One more problem that you can use with unbelievers, and this one I I won't take a lot of time explaining because you'll see an illustration of it if you listen to the public debate that I had with Dr. Gordon Stein, what is it, three years ago now at UCI. Time would not allow for me to deal with every one of the philosophical problems in his atheistic position. So I chose to use one which I felt he was least equipped to deal with. You try to exploit your opponent's weaknesses, obviously, and also to show that the very fact that he came to debate was an indictment of his worldview. I thought if I could accomplish those two things, and I'll let you be the judge of how well that was done, but if I could accomplish those two things, that would be worthwhile to show the superiority of Christianity. If you remember the debate, those of you who have listened to it, I basically challenged Dr. Stein to justify the laws of logic. Before we can go very far, you all need to know what the laws of logic are. You probably hear that preparatory word. Many of us are intimidated by logic. Many of us are intimidated by the vocabulary of logic or the thought of studying argument forms and so forth. And I wish I could take that away from you. Logic is not intimidating. It's no more intimidating than any other field of study. And Anytime we're not familiar with the vocabulary of some field, then we want to kind of back up. But all of you are capable of talking about logic and talking logically, and all of you are capable of debating the sort of thing that I'm going to be talking about here. It would probably be, well, if we had a course in logic in our church. Now, I realize that a lot of people would say of that, well, that's a strange thing to teach in Sunday school. But the more I think of it, it write me off as demented if you want to, but the more I think about it, some of you have already done that, okay? That being accomplished, the more I think about it. So many problems in our Christian life or lives in terms of communication with people, with defending our faith or witnessing or resolving doctrinal problems or coming to proper conclusions or dealing with one another come down to our inability to think clearly. And so thinking clearly, thinking logically is a virtue. It's something that is part of following the ninth commandment that we not bear false witness. Those who won't think logically are willing to bear false witness in their reasoning. Okay? And so I'm going to advocate that we have a course in logic in Sunday school. And after that is accomplished, then hopefully you'll all feel what I'm trying to get you to feel right now. Logic is not intimidating in and of itself. The intimidation is our lack of familiarity. What is logic? Logic is the study of the principles of distinguishing or distinguishing good from bad reasoning. How's that for a pedestrian definition? A study of the principles for distinguishing between good and bad reasoning, correct and incorrect reasoning. Reasoning. I'm going to oversimplify here. Reasoning always takes the form of therefore. You say this, this, this, and this, therefore that. Reasoning is drawing a conclusion from premises. What we call in the trade inferring. You infer something from something else. That's a reasoning process. Not all processes of reasoning are good ones, though. When someone says this, that, and the other, therefore this conclusion, one of the questions we want to ask is not just is the conclusion true, but does the conclusion follow from the premises? If you stop and think about it sometimes you can have a true conclusion. That is, what the conclusion says is accurate. It states the facts, but it has nothing to do with the premises or the premises do not support it adequately. All right, I'll give you just such an illustration. I know you're all sitting there waiting for this, right? If Wednesday follows Tuesday, then today is Sunday. Today is Tuesday. That's my second premise. Therefore, Today is Sunday. Now that's probably as good a mishmash of an argument as you're going to find. In the first place, you probably don't accept the first premise. The second premise is false but low. And by the way, the first and second premise don't lead to the conclusion. I mean, it's just a non sequitur of glaring proportions. A non sequitur means does not follow the premises don't lead to that conclusion. But notice my conclusion is true. Today is Sunday. So there you have a true conclusion, but a conclusion that can't be drawn from the premises at all, or drawn only in an illogical way. So logic deals with the therefore part of things. Does the conclusion follow from the premises? Not just is the conclusion true, but is the conclusion grounded in the premises? There are two general kinds of logic, and I'm being really over simple. And I'm not even sure I would agree with this in a sophisticated seminar on logic. But we traditionally distinguish between deductive inferences and inductive inferences. A deductive inference is one where the conclusion follows with necessity from the premises with necessity. Standard illustration. All men are mortal. Socrates is a man. Therefore Socrates is mortal. If the premises are true, does the conclusion follow with necessity? And the answer to that is yes. If it's true that all men are mortal, and if it is true that Socrates is a man, then of necessity, Socrates is mortal. If someone were to bring evidence to our attention that Socrates was not mortal, that he never died, then what we would say is, well, that may be true, that Socrates didn't die and therefore he's not mortal. But then you're going to have to change one of your premises because either all men are not mortal or Socrates is not a man. But given that all men are mortal and Socrates is a man of necessity, the conclusion follows. Not all arguments are in that deductive form, though some arguments are what we call inductive, where we go gathering information, particular pieces of evidence, and we try to generalize a conclusion from the evidence. Let me give you an example of an inductive argument. An inductive argument. In an inductive argument, the conclusion follows with probability from the premises, but not necessity. Here are my pieces of evidence. I've been watching my neighborhood over this last week and I noticed that the person across the street has had newspaper after newspaper after newspaper pile up on their driveway one day after another. I notice they have not mowed their lawn nor drawn their shades. There have been no lights on at night. I have not seen their garage door, open or close and assume for purposes of argument. I've been watching all day long. Each one of those is a premise in my argument. Therefore, I conclude I infer with probability that they are either dead or on vacation. Now, is that a good argument? Well, please don't tell me whether it is or not. This is for illustration. If you think that that's pretty strong evidence, then you'll think that's a pretty good inductive argument. And if you think that a lot more is needed to draw that conclusion, you'd say that's a weak argument. But inductive arguments are evaluated as to their strength or weakness based usually upon the pool of relevant data. Is there more relevant data that should be in the pool of premises before I draw that conclusion? So we have inductive and we have deductive arguments. It so happens that there are certain laws or principles that govern all arguments, whether deductive or inductive. And these are called the laws of logic. Here is a law of logic. It's called modus ponens for you Latin buffs. Modus ponens says if your first premise is an if, then premise, and it goes like this. If P then Q, that's your first premise. And if your second premise is P, the assertion of the antecedent in the conditional expression in premise one, the vocabulary is intimidating, isn't it? If your first premise, if P, then Q, and your second premise P, the conclusion always follows, which is what Q. If P then Q, I assert P, I draw the conclusion Q. Here's another good form of argumentation, and it is always valid. If P then Q not Q. That is, you deny the consequent in the first premise. If P then Q not Q, therefore not P. If it is true that Q follows from P logically and you know that Q is false, then you know P is false. Also modus tollens method of negation. And then we have disjunctive syllogism. Here's another one that you'll all enjoy. This one. A or B A or B not A, therefore B. It turns out that every argument that fills those forms will be a valid argument. That doesn't mean that everyone's going to have a true conclusion. That all depends on which premises you use. But let's see if we can fill those in. Just to give you an idea of what the laws of logic look like when they're applied, let's take disjunctive syllogism. A or B, not A, therefore B. It is Sunday or Monday, but it's not Monday, therefore it is Sunday. That follows from the premises. You don't even have to look at a calendar to check the conclusion if the premises are true that it's Monday or Sunday. If it's Sunday or Monday and you know it's not Monday, you don't have to do any more research in the world. You can just draw the conclusion. It is Sunday. That assumes that the first premise is acceptable. Okay, let's try modus tollens here. No, no, no. I'd like to use an example of what's called affirming the consequent instead of denying the consequent and therefore denying the antecedent in a conditional statement. If P, then Q will sometimes, and this happens not just sometimes, many times. If P then Q, the person will affirm Q and therefore say, I affirm P. That is, if P then Q. I know Q is true, therefore I know P is true. It's a very bad form of argument, and I think I can illustrate it in the way I do in the high school. If Shakespeare wrote Paradise Lost, then Shakespeare is a great author. The first premise is a conditional statement that begins, if Shakespeare wrote Paradise Lost. And I draw from that that if Shakespeare wrote Paradise Lost, he is a great author. And I don't think anybody is going to dispute that. I mean, if you know the history of English literature, whoever wrote Paradise Lost was a great author. And if Shakespeare was the guy, then he's a great author. Okay, now my next premise is Shakespeare was a great author. You all know that. And what do I conclude? Therefore, Shakespeare wrote Paradise Lost, which is not true because John Milton wrote Paradise Lost. But if Shakespeare wrote it, he's great, and we know that he's great, so he must have written it. That is an illogical form of reasoning. And every argument that fills that form, if P, then Q, Q therefore P, will likewise be fallacious even if the conclusion is true. I've already shown you how you can have a true conclusion, but very poor reasoning leading to it. Now, when we go and we generalize these methods of reasoning and put them in formal summary notation, if P, then Q, P, therefore Q. We're dealing with a law of logic. Now, that's all by way of introduction, what's the argument with the unbeliever? The argument with the unbeliever, like Dr. Stein, who is a naturalist, a materialist, and an atheist, is in his worldview, there could be no laws of logic. There could be no laws of logic. Why would that be? What is characteristic of a law of logic. First of all, a law of logic is the expression of something that is not material. The laws of logic are not the sort of thing that you can feed to your dog or that you can trip over at night. They aren't material things in this world at all. The laws of logic are immaterial. But in a materialist universe there aren't any immaterial things at all. Moreover, the laws of logic. Another way of putting it is the laws of logic are abstract, abstract rather than particular. And in a materialist view of the world, there are no abstract things. There are just particular things that you can touch and feel. Moreover, the laws of logic are universal. That is to say, a law of logic won't do you any good if it's subject to exception. Because then when you argue with someone and you appeal to a law of logic, the person can always say, oh, yeah, but this is the exception to that rule. The laws of logic are useless unless they are universal. But now how can a materialist who can only encounter particular experiences justify a universal truth at all? He would have to know every argument, wouldn't he? Every possible argument, every argument that's ever been used about every subject before he could say, oh, the law of modus ponens is universally true. See, he can't say it's universally true unless he has universal knowledge, which is to say, unless he's omniscient. And he can't say that the law of logic is true at all, because there are no laws in a materialist universe. There's just the particulars in the way that we happen to behave. So the laws of logic are in their very nature something that do not comport with the unbeliever, the atheistic unbelievers view of the world. On his view of the world, there ought not to be laws of logic. There cannot be laws of logic, because the laws of logic have characteristics that won't fit in his worldview. And yet, you know, because some of you have been in college courses, some of these sophomoric atheists who get to teach logic courses think that logic is their best tool against Christianity. That's always been a laugh to me, because on their view of the world there wouldn't be any logic or logic courses. But if there isn't logic or logic courses possible in an atheistic world, nor is debate possible, because debate is evaluated according to whether we keep or break the laws of logic. Right, and that's what I was getting at. And if you listen to the tape, you might say, oh, that's what that was all about when I said that if Dr. Stein were true to his worldview, he would not have shown up to the debate tonight because if he was true to his worldview, he'd have to renounce the laws of logic. And in so doing, he'd have to renounce debate as well. Now, you don't have to get into a formal setting and do this publicly. You can say the same thing to your atheistic, materialistic, naturalistic, unbelieving friend over a cup of coffee. You can say, well, why are we even having this conversation and worrying about keeping the laws of logic? Because on your worldview there can't be laws of logic. That's interesting. And I'll conclude with this final observation. If the atheist cannot support laws of logic, the atheist cannot be upset if I violated them. See, when the atheist says, well, you're being illogical. And I'll say, well, but in your worldview that shouldn't be any problem because logic doesn't have any bearing in your world worldview. And the second thing is that since he knows he's going to have to use logic, he's going to have to conclude that we are correct before he even sets out to prove that we are wrong. Because the Christian worldview, you see, gives the foundation for the laws of logic. A long time ago I used the illustration that comes from Dr. Van Till of a young child sitting on his father's lap, slapping his father's face. Van Til says, that's the way it is with unbelievers slapping the face of our heavenly Father. If he were not supporting them, they couldn't do it in the first place. And we need to point that out to the unbeliever. If you were not using my worldview, you would not be able to insult my worldview because only my worldview supports the science, logic, ethics and human dignity that you want to appeal to in your argument. Okay, questions on today's lesson. First of all, listing and so forth. Plato was not a materialist. In fact, Plato hated the material world. He thought we ought to get away from the material world that forms and reason and so forth. Plato was not a materialist. In fact, Plato hated the material world. He thought we ought to get away from the material world that forms and reason and so forth. Forth what we should be interested in. So I'm going to put him in the religious category, someone who grants a, if you will, spiritual realm or domain. And I'll be dealing with him in the future. Very simply though, what I would Say, with Plato is Plato could never know the forms because everything on his worldview creates an infinite regress of knowledge. There'd have to be a form for a form for a form. And I've got a long paper I did in graduate school on that that explicates that more. And I'm going to try to bring it down to a more pedestrian level. But essentially, Plato would have to have infinite knowledge in order to know anything at all about these laws of logic. And I'll try to show you why.

Okay, Jay, don't unbelievers really tie laws of logic to a worldview that is universal and on its own grounds can be negated by the worldview? They're not really just hanging those laws and logic out there, saying it has the foundation of the universe, the worldview, but they're being very pediatric when they select what they're deciding is universal as their review to base things like law.

Yeah, there are unbelievers who will say conceptual truths are universal in nature. But what I'm saying is, well, then, since you're a materialist and an atheist, there shouldn't be any universal laws at all. And I know this is going to surprise you. There are people who are college grad. There are people who are philosophy majors, college graduates, who, when you put that to them, sometimes they'll stop and they'll reflect and they'll say, you know, it's the first time I thought about that. Isn't that amazing? And it is, because they are so. They just, their instructors have just taught them to imbibe this. You can have the particulars in your science classes and the universals in your logic classes, and you got to bring the two together and so forth. But then the question is, well, how can you bring those two together? In your worldview, there are only particulars. Or you can go with Plato. In your worldview, there are only universals, really. And the particulars don't have real meaning, don't have reality to them. And the first time the one and the many have got to be brought together is something of a crisis intellectually for an unbeliever. Okay, questions about today's sermon.