The "name one" fallacy.

When I was in the navy, this guy walked up to me and said, “I can prove that anything you do is selfish.” My curiosity piqued, I said, “Okay, go ahead.” He said, “Try to think of something that’s not selfish, and I’ll show you that it’s selfish.” I began talking about acts of self-sacrifice and things like that, and with each example I gave him, he was able to construe it in such a way that it appeared to be a selfish act. I told him about this time I let some girl take advantage of me. I’d do anything for her, and she treated me badly. He told me I was a masochist, and I liked being treated badly, so I was really acting selfishly in fulfilling my masochistic desires. I lost the debate, because I couldn’t think of anything that didn’t turn out to be selfish by his construal.

If I could go back in time, I would’ve handled the situation a lot differently. Hopefully, it would’ve gone something like this:

Egoist: I can prove that everything you do is selfish.

Sam: Okay, go ahead.

Egoist: Try to think of something that’s not selfish.

Sam: I can’t think of anything.

Egoist: See? That proves everything you do is selfish.

Sam: No, that just proves that I can’t think of anything. How does it follow that just because I can’t think of an example of an unselfish act that there therefore are no unselfish acts?

It doesn’t follow. The fact that I can’t think of an unselfish act only says something about my state of knowledge. It doesn’t say anything at all about the existence of unselfish acts. At best, all he proved was that I was ignorant.

This is just one example of a particular kind of argument people use. I call it the “Name one” argument. It’s where you claim that a certain kind of thing exists, and the other person says, “Name one.” If you can’t name one, then they think they’ve won the debate.

A few examples off the top of my head include unselfish acts, objective moral values, and a good reason for God to create a world with evil (see earlier blog). That’s not to say that you couldn’t think of examples of each, because I think you can. My point is that even if you couldn’t, it wouldn’t follow that no such things existed.

The “name one” argument is a fallacy, because it doesn’t follow that just because I can’t name one that there therefore isn’t one. This fallacy falls under a broader fallacy known as the red herring fallacy. A red herring fallacy is basically where you change the subject in such a subtle way that it isn’t obvious you changed the subject. It seems to work on a lot of people, because the new subject is harder to deal with than the first, and if the victim of the red herring can’t solve the second subject, it makes it look like he can’t solve the first.

The change in subject with the “name one” fallacy is from “The existence of a particular kind of thing,” to “Your knowledge of examples of a particular kind of thing.” It’s possible to know that there are members of a particular kind of thing without necessarily being able to name of them. For example, I know there are people who live in Paraguay, but I can’t name a single one of them. Just because I can’t name any people in Paraguay doesn’t mean there are no people in Paraguay, or even that I’m not justified in believing there are.

To continue, see More on the "name one" fallacy.

EDIT - 1/3/2024: It looks like what I was calling a "name one" fallacy is really the fallacy of argument from ignorance. My ignorance about specific examples was being used as evidence that there are no such examples, which doesn't follow.

The arrogance fallacy

I'm taking a comparative religion class, and that tempts me to make comments in my blog about things we're covering and discussions that go on in class. Lately, we've been talking about Hinduism. Hinduism is new to most people in the class, so naturally after learning about it, they've all got questions and difficulties with it. I have some difficulties with it, too, but that's not what I'm writing this blog about.

I'm writing this blog because I have a difficulty with one of the student's objections. There was one student in there who claimed that she could never be a Hindu, because there were a couple of things she found in the Hindu worldview to be arrogant. I can't remember what the first one was, but the second one was because of the Hindu view on reincarnation. You see, most people start off as ants or something and advance to higher types of animals automatically. Karma doesn't apply until you reach the human state, and the reason is because only humans have the mental capacity to be morally responsible. The girl in my class thought it was arrogant of us humans to think we're somehow more intelligent than other animals, and she rejected Hinduism for that reason.

This is just one example of why I'm writing this blog. Let me give another example. Last year, I was talking to a guy in my philosophy class about the Jewish worldview, specifically about the idea that YHWH chose them. His objection to the whole view was that it was arrogant.

These sentiments aren't new. I hear them all the time. The objection I have to these kinds of sentiments is that they're irrelevent. The only reason anybody should accept a religious view is because it's true. If it's true, they should accept it, and it's it's false, they should reject it. But whether it's arrogant or not has no bearing whatsoever on whether or not it's true. Why even raise the issue? I could care less if the Jews or the Calvinists are arrogant in thinking God chose them. I'm only interested in whether it's true that God chose them. The same goes with Hinduism. Who cares if humans are arrogant in thinking they are smarter than other animals? I'm only interested to know if it's true.

Why the resurrection is so important

Yesterday, I mentioned that Jesus being the Christ and Jesus rising from the dead are essential aspects of Christianity, without which, you'd just have a different religion or no religion at all. Now I want to say why I think that.

Well, I guess I already said why I think "Christ" is essential. Christ is what Christianity is all about. But I also said it means something specific in a Jewish context. Now don't get me wrong. Jewish views about the Christ were quite diverse in and around the time of Jesus. Not all Jews were especting a Christ, some expected a Christ who would reign once Israel became a sovereign nation, others expected a Christ who would be instrumental in liberating Israel, and others expected two Christs.

Christ comes from the Greek word, christos, which means "anointed" or "annointed one." The Hebrew word with the same meaning is mischiac, or messiah. In Jewish tradition it could refer to a king, a priest, or a prophet. Most often, however, it referred to a king. Anointing was part of the coronation ceremony of the kings of Israel, so all kings of Israel were considered "anointed ones" or "messiahs." But the term wasn't limited to Israelite kings. It was also used of Antiochus IV Epiphanes in the book of Daniel. (Yes, I realize that's a controversial claim.) It's even used of the Persian king, Cyrus, in Isaiah 45:1. Messiah, then, is basically equivalent with "king" in most cases.

The whole idea of a coming messiah in Jewish eschatology comes from a promise God made to Israel--that they would never fail to have a king seated on the throne of David. Shortly after the Babylonian exile began, the last of the Israelite kings was deposed, and God's promise seemed to have been broken. But rather than completely abandon their belief in YHWY or that YHWY had violated his promise or didn't make any promise at all, the belief arose that YHWY would restore the throne to David. And so you have countless prophecies in the Old Testament that refer to David in an eschatological sense. Ezekiel 37 is a good example. That's the vision of the valley of dry bones which, as God explains, is a symbol referring to the reunification of Judah and Israel. In v. 24, God says that David will be their king, and in the next verse it says David will be their prince forever.

That's basically the messianic hope. Although views varied on how it would actually play out in history, the basic plot is that either David himself or some descendent of David would come to rule over a reunited Israel free from foreign rule, and the kingdom would last forever.

With this in mind, it's perfectly understandable why Paul would say "Christ crucified" is a stumbling block to Jews (1 Corinthians 1:23). Jesus died without doing what the messiah was expected to do. He failed. He was just one of about a dozen other pretenders in the first century whose messianic pretentions ended in death. Most Jews even today, if asked why they reject Jesus as the Christ, will say the same thing. He died without fulfilling the messianic role.

The reason the resurrection is so important is because without it, the Jews are entirely right. If Jesus is dead, then he's not the Christ, and if he's not the Christ, then Christianity is not true. But if Jesus was raised from the dead, he may yet be the messiah.

But, a person might object, even if he's still alive, he hasn't fulfilled the messianic role. Quite so. If he hasn't fulfilled the messianic role, then why think he's the Christ at all?

That's a good question, and thankfully for me, I have two responses. First, imagine some descendent of David is born, and suppose his parents begin to imagine, "Do you think he might be the messiah?" Then they get up the next morning, and they notice that the world is as it was before. Would it be reasonable for them to conclude, "Well, he didn't do what the messiah was supposed to do, so I guess he's not the messiah"? Of course not. As long as he's still alive, there are things he has yet to do. Perhaps some day he will fulfill the messianic role. So he can't be excluded from being the messiah merely on the basis that he hasn't fulfilled the role yet. Only when he dies is his chance over. Since Jesus is still alive, he can't be ruled out.

Second, Jesus claimed to be the Christ. Now I know that some people disagree, but that's beyond the scope of this blog. Assume, for the sake of argument, that Jesus did claim to be the Christ. Now that, by itself, is not enough to establish that he is. After all, lots of people in the first century claimed to be the Christ. Josephus tells us that during the war with Rome, there were at least three people all claiming to be the Christ and fighting each other while at the same time fighting the Romans. But it seems to me that it would be an odd coincidence if, of all people to rise from the dead, it's this person named Jesus who claims to be the Christ--to be sent from God. If Jesus really did rise from the dead, I think that is proof to any reasonable person that his claim to be the Christ is true.

So the resurrection is important for two reasons. First, without it, Jesus isn't the Christ. He can't be the Christ if he's dead, but as long as he's alive, it remains to be seen if he fulfills the messianic role. Second, the resurrection serves at verification that Jesus' claim to be the Christ is true. Now we don't have to sit around and wait to see if Jesus fulfills the messianic role. Now we have reason to be confident that he will. Jesus is the Christ; the Christ fulfills the messianic role; therefore, Jesus will fulfill the messianic role. We're just waiting.

Man, I can see that I've opened up a whole can of worms that is going to require a whole bunch more blogs before I get it all out.

What is Christianity?

The precise definition of Christianity has always seemed a bit fluid. Even in the second century, the Gnostics and the orthodox had disagreements on what entailed “true Chrisitianity.” In the last hundred and fifty years or so, these kinds of debates have exploded.

Now a lot of us don’t like the idea that there’s such a thing as “true Chrisitianity,” because once you start being specific, then you start excluding people, and that seems intolerant. But really, there must be a minimal set of necessary conditions for something to qualify as Christian. Otherwise, we might as well call Wiccans Christians, and also call atheists Christians. There has to be something that makes a religion what it is and not something else.

Maybe there’s room for debate on whether some groups can legitimately be called Christians or not, but what I want to give is a bare bones minimum requirement for what counts as Christian. I already know that some of what I’m going to say will be controversial, because there are some people out there calling themselves Christians who don’t fit these criteria. But I am confident in claiming they are not Christian, because I’m quite sure about this minimum requirement I’m about to spell out.

First, and most obviously, there has to be a God. And God isn’t just a projection of the mind—a theological construct one superimposes on the universe. God is a real being who exists independently of human thought.

Second, Jesus is the Christ. I think this is just as obvious. I mean think of the word “Christian.” You can’t have Christianity without Christ. And Christ means something in its historical context. I’ll have to go into that in another blog another time.

Third, the early Jesus people, who were called Christians because they followed a Christ, had a message—a gospel—that they were spreading. This gospel defined what their movement was all about—what the Christian movement was all about. Paul spells out that gospel message in 1 Corinthians 15. He says that he received this gospel and passed it on to the Corinthians at the beginning. He reminds them of its contents in a formulaic way—apparently the way it had been preserved in oral tradition from the time Paul first received it. It goes like this:

that Christ died for our sins according to the scriptures
and that he was buried
and that he was raised on the third day according to the scriptures

Now of course there’s much more to it than that, but this seems to be the bare bones minimum of what Christianity was all about. But a lot is entailed in it.

First, as I’ve said before, there’s “Christ,” which refers specifically to Jesus of Nazareth.

Second, Christ died for sins. A lot is entailed in that statement, too. A sin is basically a violation of God’s law, which is moral in nature. One can sin by failing to do what he ought to do, as James tells us. A person can also sin by doing what they ought not to do, as Paul tells us. But unless there is a moral law, there can be no violation of a moral law, so there can be no sin. If there’s no sin, then Christ didn’t die for sins. So this one statement implies that there’s such a thing as right and wrong, that people violate this law of right and wrong, and that Christ died for the sake of those violations. As this is spelled out in other places, Christ atoned for our sins.

Also, Christ would not have needed to atone for our sins if there were no accountability for them. So this also implies some sort of judgment. God is apparently holding us accountable for our behavior. (How wildly unpopular--a punitive God!)

Third, Christ was raised from the dead. This was not some symbolic way of expressing Christ’s continued presence in the heart of his disciples after his death. They actually believed he was raised from the dead. Paul goes on to quote appearance traditions, and having personally known those to whom he refers (as is evident in Galatians), it is highly doubtful that he had a big misunderstanding. The whole purpose of one of his visits to Jerusalem was to lay before them the gospel that he preaches to the Gentiles, and it is hard to imagine such a visit that didn’t discuss what Paul understood the gospel to be.

So to summarize, here is a basic list of things I take Christianity to entail:

1. There is a God—specifically the Jewish God, YHWH.
2. There is such a thing as right and wrong.
3. People disobey the moral law, and God holds them accountable.
4. Christ died to atone for our sins—our disobedience to the moral law.
5. Christ was raised from the dead.

I know more could be added to this list, but I am confident that if all five of these are true, then Christianity is true. If any one of these five are false, then Christianity is false.

This list excludes some people as being Christians. I’ll go ahead and be crass and tell you who I was thinking of when I wrote this. I was thinking specifically of John Shelby Spong (although there are several others). If you read his writings carefully, you’ll see that Spong doesn’t really even believe there’s any God in the objective sense. God, for him, is just an idea. The impression I get is that he’s creating a new religion altogether that bears so little resemblance to Christianity, that he might as well call it something else. If we go on letting “Christianity” be defined in any way Spong or whoever makes up, then the word will cease to have any meaning at all. A word that signifies everything signifies nothing.

A parody addressing those who deny logic

The reason I have this fixation in a lot of my blogs on logic is because I'm in the unfortunate situation of going to a college with only one philosophy teacher, and he doesn't put a high value on logic. He wastes a lot of our time by having us read a lot of irrational nonsense. In classroom and email discussions, I can never advance an argument without somebody taking issue with my use of logic. Consequently, I spend the majority of my time defending logic. You can't reason with people who don't believe in logic, so you have to settle the logic issue before you can argue about anything else.

One day last year, I was just really frustrated with having to defend logic against arguments such as, "You're just using western logic," and "Your use of western logic is biased and dogmatic," which aren't really arguments at all. In my frustration, I wrote this parody. A few people in the class found it entertaining, so I thought I'd post it on my blog. The reference to "speaking differently" comes from an article our teacher had us read by a couple of kooks who thought logic was a matter of personal preference, and they preferred to "speak differently."

A feller walked into the Wingate Inn, and we had the following conversation:

Feller: Hey, can I use your phone?

Sam: Yeah, just be sure to dial 9 to get an outside line.

The feller starts to dial the number, but then stops.

Feller: Did you say I had to dial a 9 to get an outside line?

Sam: No, you don’t have to dial 9. Just dial the number.

Feller: Okay.

He tries to dial the number, but it doesn’t work.

Feller: The phone doesn’t work.

Sam: Did you dial 9 first?

Feller: No, you said I didn’t have to dial 9.

Sam: That’s right. You have to dial 9 first.

Feller: Then why did you just tell me I don’t have to dial 9 first?

Sam: Because you don’t.

Feller: Then why did you say that I do?

Sam: Because you do.

Feller: You're screwing with me.

Sam: Why do you say that?

Feller: Well, first you said I have to dial 9 to get an outside line, and
then you said I don’t have to dial 9 to get an outside line.

Sam: That’s right.

Feller: Well, you’re contradicting yourself. They can’t both be right.

Sam: Oh, you’re just using Western logic.

Feller: Listen, I either have to dial a 9 or I don’t.

Sam: Now you’re being biased and dogmatic.

Feller: You’re being crazy.

Sam: I’m only speaking differently.

Feller: You can say that again.

Sam: I’m not speaking differently.

In the end, “western logic” helped the feller figured out that he actually did have to dial a 9 to get an outside line, and that I was wrong all those times I told him he didn’t. Maybe the phone was being biased and dogmatic, too.

I'm right and you're wrong.

"Christians are arrogant, because they think they're right and everybody else is wrong." --the generic non-Christian

Really? It seems to me that Christians aren't being arrogant; they're being logical. Not only that, but they're also being honest. Lemme explain.

You see, everybody has a point of view. That is, they have certain beliefs about the way things are. They hold certain things to be true about the world. To believe something merely means to think that something is true. If I believe that my cat is pregnant, that means I think it's true that my cat is pregnant. I hold that "Sam's cat is pregnant" is a true and accurate description of reality.

By the law of non-contradiction, if one thing is true, then it's opposite is false. If it's true that my cat is pregnant, then it's false to say my cat is not pregnant. Naturally then, if I really believe that my cat is pregnant, and somebody else comes along who thinks my cat is not pregant, I'm going to think they're mistaken. My cat can't be both pregnant and not pregnant at the same time and in the same sense. The law of non-contradiction would have to be violated before that could happen.

Since everybody has certain beliefs about reality, and to believe something is to think it's true, then everybody thinks they are right. Think about. Imagine the idea of having a belief you think is wrong. Well, if you thought it was wrong, it wouldn't really be your belief, would it? It's only your belief if you think it's right. So everybody thinks their beliefs are right.

And if they are logical, they are going to think those who disagree with them are wrong. And they do, too. Even people who object to Christians for thinking they are right and everybody else is wrong are of the opinion that Christians are wrong. That's why they have this disagreement with them. By its very nature, to disagree with somebody is to think they are wrong, and to hold an opinion contrary to their's which they think is right.

At least Christians are honest about this. Christians, if they have not been shamed into silence, will admit that they think they are right, and those who disagree with them are wrong. That's because Christianity is a rational religion. The laws of logic are an essential aspect of the Christian worldview. If Christians are arrogant merely for thinking they are right and thinking others are wrong, then everybody is arrogant who believes in logic.

Now don't misunderstand me. I'm not saying anything about the certainty with which Christians hold their views. As I said in an earlier blog, there are only a handful of things I claim to know with absolute certainty, and the truth of Christianity is not one of them. Most things I believe, I believe them with varying degrees of certainty. That means as strongly as I may believe something, I will acknowledge the possibility that I may be wrong, and that includes my belief in Christianity. Saying, "I'm right and you're wrong," does not negate my lack of absolute certainty; it only expresses my belief. Obviously, if I believe something, then I think it's right, and logic forces me to think dissenters are wrong.

Frankly, I think people who stick their noses up at Christians merely for thinking their religion is true while everybody else's is wrong are just being hypocritical. A hypocrit is somebody who does the very thing they object to everybody else doing. People who object to Christians just because Christians think they're right and everybody else is wrong are doing the very same thing. They think the Christians are wrong and they are right. That's why they take issue with the Christians. They wouldn't be objecting unless they thought the Christians were wrong.

Why can't we all just be honest? We all have a point of view, and often, our viewpoints differ. That means we have disagreements. We think we're right and those who differ with us are wrong. Let's just admit it. Only by facing this fact can we enter into meanful dialogue about our differences. If we keep throwing up the arrogant mantra, all we're going to accomplish is stopping all conversation. If it offends you that other people think you're wrong, you just need to get a grip.

More on the problem of evil

Yesterday, I posted about Alvin Plantinga's solution to the deductive problem of evil (DPE). The first premise in the DPE states that "If God exists, evil does not exist," which is based on the idea that "God exists," is somehow imcompatible with "Evil exists." There's an implicit contradiction that needs to be made explicit by adding some true premise such that when it is added, and when the set is taken to its logical conclusion, it results in an explicit contradiction.

Plantinga said that so far nobody has come up with the necessary premise to demonstrate that "God exists" is incompatible with "Evil exists." But I thought it just wouldn't be right if I didn't say something about how this conclusion was arrived at.

Remember that God is being understood as a being who is all knowing, all powerful, and all good. The argument is that if he's all knowing, then he knows how to create a world without evil. If he's all powerful, then he is able to create a world without evil. If he's all good, then he has a desire to create a world without evil. With the know-how, the power, and the desire to create a world without evil, God's existence is said to be incompatible with evil. Since evil exists, either God lacks the ability, the know-how, or the desire. In either case, the God described as being all knowing, all powerful, and all good does not exist.

I don't have a problem with the idea that if God is all good then God has a desire to create a world without evil. But the God of the Bible is revealed as having both a sovereign will and a moral will, and they are not always the same. For example, in Ezekiel 33:11, God says, "I take no pleasure in the death of the wicked, but rather that the wicked turn from his way and live." God doesn't want the wicked to die, and yet he is the one who judges them for their wickedness. Clearly, then, the Bible reveals a God whose sovereign acts are sometimes contrary to his desires.

But why is that? Well, in the case of not choosing to creating a world free of evil, it's because he either lacks the power or he lacks the know-how, according to the DPE.

While I don't have a problem with the idea that God being all good implies that God has a desire to create a world free of evil, I do have a problem with the second two positions. I don't think God being all powerful implies that God is able to create a world free of evil, nor that God being all knowing implies that God knows how to create a world free of evil. I'll explain why.

First, let's look at the all powerful part. I asked a guy in school one time if he could draw me a four-sided triangle on a sheet of paper. He said he couldn't do it. I said, "Well, do you think you could do it if you worked out, lifted weights, and got a lot stronger?" He said, "No." You see, lack of power has nothing to do with his inability to draw a four-sided triangle. It isn't strength that prevents him from doing it. It's because a four-sided triangle is a contradiction in terms. If a shape is four-sided, then it's not a triangle, and if it's a triangle, then it doesn't have four sides.

In the same way, God can't accomplish meaningless tasks. God can't be completely honest and tell lies at the same time. That's why the Bible says "it is impossible for God to lie" (Hebrews 6:18). Likewise, God can't make square triangles, exist and not exist at the same time, know things he doesn't know, or create rocks too heavy for an all powerful God to lift. All of these describe meaningless tasks, because they entail logical contradictions.

I say all that to say this. It isn't necessarily the case that if God is all powerful that he could therefore create a world without evil. The reason is that doing so may be inconsistent with some other purpose God has which entails evil. Plantinga suggested that perhaps God has a good reason for evil. If there is a good reason for evil, then it would be impossible for God to be all good and all powerful and not create a world with evil in it. To do so would entail a logical contradiction. God would have to be good and not good at the same time.

Now let's look at the all knowing part. Supposedly if God is all knowing, then he knows how to create a world with evil in it. Let's think carefully about this, now. What does it mean to know something? Knowledge has traditionally been defined as "justified true belief." Not that God needs anything proved to him or anything, but at a bare minimum, before you can know something, that thing first has to be true, right? You can't know that the earth is flat, can you? Does God know that the earth is flat? No, because the earth is not flat. Basically what I'm getting at is that God only knows things that are true.

The reason I make such a banal point is so that I can make this point. God can only know how to create a world without evil in it if there is a way to create a world without evil in it that is consistent with his good character. Now if there really is a good reason for evil, and if God is good, then it is inconsistent with God's goodness to create a world without evil in it. In that case, God doesn't know how to create a world without evil in it for the simple reason that there is no way for him to create a world without evil in it. You can't know something if there's nothing to know, but that doesn't mean God isn't all knowing. To be all knowing means to know everything there is to know.

I think that's about all I have to say for now.

Alvin Plantinga's solution to the deductive problem of evil

Back in December I was talking to a friend of mine about Alvin Plantinga's solution to the deductive problem of evil (DPE) in God, Freedom, and Evil. The DPE goes something like this:

1. If God exists, evil does not exist.
2. Evil exists.
3. Therefore, God does not exist.

where "God" is understood as a being who is all knowing, all powerful, and all good.

Plantinga's solution was basically to show that the first premise is not true. The first premise is based on the idea that "God exists" is inconsistent with "Evil exists," so all Plantinga did was undermine that idea by showing that "God exists" is not inconsistent with "Evil exists."

There are two ways they might contradict each other--explicitly or implicitly. An explicit contradiction is a situation where you have A and not-A. For example, "God exists," explicitly contradicts, "God does not exist."

And implicit contradiction is where two claims lead to an explicit contradiction when taken to their logical conclusions. For example, "All men are mortal," implicitly contradicts "Socrates is not mortal." The way to show that the two claims are contradictory is by adding a true premise to the set such that together with one of the other premises entails the negation of the final premise. To the set, "All men are mortal," and "Socrates is not mortal," can be added "Socrates is a man." Then you can draw out the contradiction like this:

1. All men are mortal.
2. Socrates is a man.
3. Therefore, Socrates is mortal.

But "Socrates is mortal," explicitly contradicts "Socrates is not mortal," so by adding "Socrates is a man," it can be shown that "All men are mortal" implicitly contradicts "Socrates is not mortal."

To solve the DPE, Plantinga first noted that there is no explicit contradiction between "God exists" and "Evil exists." If they contradict at all, it must be implicitly, which means some true premise must be found that when added to the set, results in an explicit contradiction. Second, Plantinga pointed out that no such premise had yet been found; therefore, nobody had yet demonstrated that there is a contradiction. Third, rather than sit around hoping nobody would ever discover the necessary premise, Plantinga came up with a way to show that no premise would ever be found. He did it by proving that "God exists," does not contradict, "Evil exists."

The way he went about proving that "God exists" is logically consistent with "Evil exists," is by finding a premise that is possibly true, and that together with "God exists," entails that "Evil exists." If "God exists" together with some other premise logically entails that "Evil exists," then "God exists" and "Evil exists" must be logically consistent.

He claimed that the premise need not necessarily be true. It only had to describe a possible state of affairs. When I read that, I wasn't clear on why it needed to only be possible.

That brings me to my own contribution to Plantinga's argument. After thinking about it, I discovered why, and I think I can explain using possible world semantics. You see, if "God exists" really does contradict "Evil exists," then it's not even possible for both of them to be true at the same time and in the same sense. That's the law of non-contradiction. Using possible world semantics, you would say that "God exists" and "Evil exists" are not true in any possible world. So all you have to do is find some possible world--some possible state of affairs--in which "God exists" and "Evil exists" are both true. Here's the argument in syllogisms:

1. If two propositions are contradictory, then they cannot both be true in any possible world. (This is just the law of non-contradiction stated in possible world semantics.)
2. There is a possible world in which "God exists" and "Evil exists" are both true. (This will be demonstrated in the next syllogism.)
3. Therefore, "God exists" and "Evil exists" are not contradictory.

To prove the second premise, you can form another syllogism:

4. God exists.
5. God created a world with evil and has a good reason for doing so.
6. Therefore, evil exists.

The fifth premise is the premise Plantinga added to show that "God exists" and "Evil exists" are logically compatible. The question now is whether or not the fifth premise is actually possible. Remember that it need not be actually true. It only needs to describe a possible state of affairs. In other words, it has to be true in some possible world. If it's true in some possible world, then the second premise in the former syllogism is true.

To show that the fifth premise is possible, all you have to ask, really, is whether or not there can be such a thing as a good reason for an evil. Several scenarios can then be mentioned. For example, dentists cause pain in order to fix teeth. It may be objected that this scenario doesn't apply to God since God could fix teeth without causing pain, but all we're trying to prove is whether or not it's possible for there to be a good reason for evil, and the scenario shows that it is. If it's possible for there to be a good reason for evil, then it's also possible that God has a good reason for evil.

And that's all that's necessary to solve the deductive problem of evil.