GPLindsey

Some definitions for this post:

To "know" something is to hold that it is true based on sound logic and/or sufficient evidence.

To "believe" something is to hold that it is true even though it lacks convincing support from sound logic and/or sufficent evidence--the belief comes from faith or intuition or by jumping to conclusions based on scant evidence.

To "think" something is true is not an assertion that one knows something is true--rather, it is a probabilistic conclusion based on the weight of he evidence.

Time and again, I've seen apologists try to argue with atheists that our conclusion that there is no God is illogical, because we cannot "know" that God does not exist. Instead of being atheists, we should be agnostics. They make two mistakes. First, they confuse the fact that atheism concerns belief whereas agnosticism concerns the nature of knowledge. There is nothing at all illogical in saying "I don't believe in God", and the theist is simply changing the subject when they then ask, "But how can you KNOW God does not exist?" For supporters of so called "weak" atheism, this is really the only response you need to give--you do not have to defend how you know God does not exist, because your position is one of belief.

The second mistake that apologists make is to abuse the verb "to know" and limit it to only one sense--knowing something with absolute, 100% certaintly. Defining it in this limited sense, they seek to impose a very low threshold for their beliefs about God and a very high threshold for the atheist position. Because God cannot be disproved with 100% certaintly, the existence of God becomes "plausible", so theists have a legitimate basis to build their faith upon. Even if the evidence suggests that there is only a .000001 chance that God exists, that is still good enough to believe it true. Conversely, because God cannot be disproved with 100% certainty, they assert that the atheist position is illogical. The evidence may suggest that there is a .999999 probablility that God does not exist (making it much more "plausible" than the other position), but that is not good enough, atheist--you need to hit 100% certainty.

This is absurd. The verb "to know" is not limited to situations where 100% certainty of the truth is attainable. Other than certain logic constructs--such as "If A is greater than B, and B is greater than C, then A is greater than C"--or definitional truths like "There are no round squares", there are precious few such situations where 100% certainty can be found. Rather, we use the word "know" to cover a broad range of circumstances where we do not have perfect knowledge, but the weight of the logic and/or evidence makes it unreasonable to withold "provisional" accceptance that something is true. It is provisional because, if stronger evidence subsequently comes to light that proves a different conclusion, than our minds can be changed. Changing our minds later based on stronger evidence does not prove that our earlier position was illogical.

An example. I know Australia is in the South Pacific, and New Zealand is next to it. However, I have never been there and have not done any research on my own to confirm that it is there. I am relying on the general public concensus that it exists, which in turn is based on the myriad testimonies from people who have been there, the references to it in geography and history books, satellite photos from NASA, etc. But does all this evidence build up to a case of 100% certainty? No. There is a remote, remote possibility that an elaborate hoax is going on, or that I've been in a coma since age 11 and I've dreamed up this imaginary world with an imaginary place called Australia, or any number of absurd alternatives. Because I can't say with 100% certainty that Australia exists, then it is "plausible" that it does not exist.

If I were to embrace the theist definition of "know", as they use it in these God debates, I would have to go around saying that I was "agnostic" as to whether Australia exists, or I could say that I "think" or "believe" Australia exists, but I couldn't say I "know" until I've hit that magical 100% certainty. Would this make any sense? Other than in apologetic debates about God, do theists really believe it is only legitimate to use the word "know" in situations where 100% certainty is attainable?

How about dinosaurs? I know that T. Rex went extinct over 65 million years ago. But I have not visited every nook and cranny of the planet Earth. There just may be a remote jungle or valley where no human has visited, where a small pod of T. Rexs have managed to hide out and reproduce for millions of years, unnoticed. A preposterous notion, but can I disprove it with 100% certainty? No. The theist would therefore say that I must be agnostic as to whether T. Rexs are extinct, and caveat my position by saying I only "think" or "believe" they are extinct.

In courtrooms in the U.S., people can be sent to jail or even to their deaths based on proof beyond a "reasonable" doubt--not all doubt. Following the theist way of looking at the word "know", juries would always have to be "agnostic" about the guilt or innocence of the accused before them. So long as the accused could present a "plausible" alternative explanation, no matter how ridiculous, we cannot say that we know they are guilty or innocent. Theists--do you think juries are being "illogical" because they can reach the conclusion that someone is guilty beyond a reasonable doubt, based on available evidence? Should they instead withhold judgment until they "know" beyond all doubt? If not, then why do you impose a higher standard on atheists when it comes to the question of God? Why is it illogical for an atheist to conclude that God does not exist, beyond a reasonable doubt, based on the available evidence?

For people who subscribe to so-called "strong atheism", I say that it is therefore legitimate to conclude that "God does not exist" or to say "I know that God does not exist," by emphasizing that the verb "to know" is not restricted to situations of 100% certainty. I think both weak and strong atheists hold that the evidence for God is extremely weak, but weak atheists make the mistake of buying into the apologist's argument that 100% certainty is required before you can say you "know." This is bogus. If you accept this position, then you should basically banish the verb "to know" from your vocabulary, and say only that you "think" or "believe" things are true. If you do that, then you are helping the theists with one of their goals--reducing all truth claims to matters of "belief" and all debates about the nature of reality to just clashing belief systems. Don't do it--be a strong atheist!

Daedalus

My particular favorite is how religious people abuse the word "believe".

You know in kids sports movies where the kid in the wheel chair or with the thick glasses overcomes adversity to get to the championship game and is getting ready to make the game winning play when his mother shouts out
"You can do it Jimmy, I believe in you!" Well, duh. He's right standing right there with the adorably tousled hair the leg braces. Of course you believe in him. What she really means is she loves him and she wants him to succeed? And it's the same way with religious people.

A person can say say "I believe in god" and mean any or all of the following:

• I believe god exists.
• I believe that what god says is true.
• I believe that god will do what he promises.

And it all seems to mush together into something else like:

• I believe god is good. I love god and want his plans to succeed.

So when you try to call them on one possible meaning they switch to another.

And then there is "to know" as in a personal relationship. Some people don't say "I know God exists" they just say "I know God."

I'm not sure I like your definitions of "to know" and "to think". You say that "to know" something shouldn't require 100% confidence, but you also say that "to think" is a conclusion based on the weight of the evidence. At what percent confidence can you justify saying "I know" instead of "I think". Certainly, if the probability of something being true were less than 50% you wouldn't want to say you think or you know it is true. I agree that if there is a 99.99999% chance of New Zealand existing then you could say you know it. But what if the probability were only 99% or 75%? Is there a non-arbitrary standard for the difference between thinking and knowing under your definitions?

I think the difference between thinking and knowing isn't the probability you calculate for it being true, but whether or not it actually is true. Basically, you can't know something that isn't true. You can think you know, but you don't, you only believe. Without wanting to start a game of dictionary tennis, I suggest different definitions:

To "think of" something is to create a mental model of something that may or may not be real or true.

To "think" something is to generally act as if your mental model of it accurately reflects reality, regardless of whether or not it does.

To "know" something is to generally act as if your mental model of it accurately reflects reality, when in fact it does.

To "believe" something is to think your mental model of it accurately reflects reality, whether or not it does.

So Columbus was able to think of the earth being flat and the earth being round. For a while he thought the earth was flat. He believed it was flat. But he didn't know the earth is flat, because the earth isn't flat. Then eventually he thought of the earth as being round. He considered the evidence and concluded that the earth being round made more sense. He started believing and thinking the earth was round instead of flat. In fact, he knew it was round.

My definitions have the advantage of being independent of the person stating what they think. Under your definition, all a theist has to do to "know" god is compute a high probability of god's existence. Under my definition a theist can claim to know whatever they want, but they probably don't. It also lets me believe things because I have strong evidence or good arguments for them, not inspite of it. And it lets religious people believe weird things without having to be totally irrational.

As a weak atheist I basically HAVE banished "to know" from my vocabulary (just ask my last boss ). I wish that more people would do the same.

GPLindsey

I agree that there is a decision to be made as to when we say we "know" something if we have less than 100% certainty vs. when we merely "think" something is true. However, the key is whether you hold it to be true--the conclusion you have reached--rather than the exact percentage threshold you used to arrive at the conclusion. Per my definitions, when I say "I think" something is true, I am not asserting that I hold it to be true, but rather that the conclusion is my best guess based on the weight of the evidence. When I say "I know" something, it means that I've crossed the threshold of reasonable doubt and hold it to be actually true. Recall taking multiple choice tests in High School--for some questions, you studied well and you have a clear memory of the correct answer, so you "know" you got it right. You are firmly convinced that your answer is true. For other questions, you were much less certain, but after scratching your head and going through a process of elimination, you decide that you "think" Answer C is the correct one. But you readily admit to yourself that you could be wrong and that "C" may not be true.

To go back to the courtroom again, in civil cases the burden of proof is "based on the preponderance of evidence", or 51%. This is a useful metaphor for "think"--it is more likely than not that Party X's accusations against Party Y are true. In criminal cases, the standard is "beyond a reasonable doubt." This means that the standard is much higher than 51%, but it is not 100% certainty. You don't have to acquit somebody just because there is an infinitely remote possibility that all the evidence is wrong--i.e., the 15 eyewitnesses were all lying; the DNA found under the dead girl's fingernails were from the accused's evil twin brother, whose existence has been a secret until now; the scratches on the accused's face that correspond to what was found under the dead girl's fingernails were actually scratches from a tree branch, etc. "Beyond a reasonable doubt" is a judgment call that each juror must make as they weigh the evidence. It is also a judgment call we must make on the question of God--is the evidence for or against his existence greater than 51%? Is it beyond a reasonable doubt?

I disagree with the idea that you cannot know something is true unless it really is true, because that just puts you into useless circles. How do we know something really is true? By the weight of the logic and evidence to support it. But I looked at that already and concluded that it is true. Ah yes, but how can you be absolutely certain that it is true? Well, if there was additional evidence out there that could bring me to the point of absolute certainty, I would look at it, but there isn't. So I'm left with what I had at the beginning, the evidence that was in front of me when I decided that I knew it was true.

Again, if the standard is 100% certainty before we can say we "know" anything, then there would be virtually no need to use the term "know" at all in our language. You couldn't even say you "know" your own name, because there is a remote possibility you were switched at birth in the hospital and you have been living under the wrong name. There was a court case with this scenario some years back (think it was on 60 Minutes), where a tragic teenage girl had to listen to an attorney in the case tell the judge that the name she has known all her life wasn't really her name. Because there is a 1 in 80 million chance that that happened to you, are you going to go around saying you "think" your name is Joe Smith, rather than you "know" that is your name?

The purpose of language is to convey meaning. What use is there in slapping "think" on every stance you take, because of the remote possibility of error, rather than saying you "think" when you believe something is likely but are not so sure, and you "know" when you are sure beyond any reasonable doubt? Doesn't the latter approach convey your meaning more clearly?

If anything, we need a new term for that tiny subset of "know" situations where we can have absolute certainty beyond all doubt. Until that happens, I'm happy to say that I know God does not exist beyond any reasonable doubt, and so should you if that is your conclusion.

So put "know" back in your vocabulary!