Be a good little atheist...

[Beth]

This was the original context:

All these other virtues are useless without a rational fact base from which to practice them.

All virtues are practiced in a world in which we never have complete knowledge, but must make assumptions based on what we do know and believe. There are many theists doing good things in this world, exercising their intelligence, compassion and other virtues for the benefit of others. Since their efforts are clearly not useless, I can only conclude that either your statement is incorrect or theists have a rational fact base they are operating from.

However, in this case, it was quite clear what was meant by "assumption". The first person to use it (which wasn't me) put it in a context where it could really only mean one thing -- something you treat as true despite a lack of evidence to justify treating it in that way.

I responded using that same meaning of 'assumption'.

Actually, no. As I was the person you were quoting, let me clarify. As I stated in post 545, Bokonon was correct regarding the definition I was thinking of. I'm not sure where you got the idea that when people use the word "assumption" it implies that there is either a lack of evidence to support that assumption or that it is immune from reconsideration if contradictory evidence is found. It is not a commonly accepted implication of the word 'assumption' and it did not occur to me that you would interpret it that way.

 

[JoelKatz]

So by 'assumption', you meant treating something as true because, and to precisely the extent, the evidence justifies treating it as true? (Specifically, in the case where the evidence suggests the claim is very, very likely but not certain to be true.) If so, of course anyone and everyone can and should do that and it's entirely unobjectionable.

This renders your original statement somewhat baffling though. To what purpose would you point this out?

 

[Beth]

So by 'assumption', you meant treating something as true because, and to precisely the extent, the evidence justifies treating it as true? (Specifically, in the case where the evidence suggests the claim is very, very likely but not certain to be true.) If so, of course anyone and everyone can and should do that and it's entirely unobjectionable.

This renders your original statement somewhat baffling though. To what purpose would you point this out?

You had stated that

All these other virtues are useless without a rational fact base from which to practice them.

My point honesty, compassion and intelligence are just as useful for theists as they are for atheists because we all must work from assumptions, not facts alone.

 

[bokonon]

So by 'assumption', you meant treating something as true because, and to precisely the extent, the evidence justifies treating it as true? (Specifically, in the case where the evidence suggests the claim is very, very likely but not certain to be true.) If so, of course anyone and everyone can and should do that and it's entirely unobjectionable.

This renders your original statement somewhat baffling though. To what purpose would you point this out?

"To precisely the extent it's justified" is overstated, in my opinion. Since our knowledge is incomplete, we don't know such things precisely.

The original statement was "All virtues are practiced in a world in which we never have complete knowledge, but must make assumptions based on what we do know and believe."

Since it clearly says the assumptions are "based on what we do know," the only thing that's baffling to me is how your reaction to the original statement was "It is never necessary to make assumptions, and it is always an error to do so."

 

[Mirrorglass]

I'm not talking about the "real meaning" of the word "assumption". It means whatever people mean by it when they use it, and I and others have amply explained the range of possible things a person might mean by "assumption".

However, in this case, it was quite clear what was meant by "assumption". The first person to use it (which wasn't me) put it in a context where it could really only mean one thing -- something you treat as true despite a lack of evidence to justify treating it in that way.

I responded using that same meaning of 'assumption'. Then someone else turned around and said that I was wrong using a different meaning of 'assumption' (something whose truth is not important, but that we suppose is true to find dependent implications which we acknowledge are dependent on the truth of the thing assumed).

This is the same trick a theist might use when an atheist says he doesn't believe in God. "God is everything. You don't believe in everything." Then he finds some dictionary or something that lists "everything" as a possible meaning for god and accuses the atheist of thinking he's "smarter than the dictionary".

It's an utterly dishonest tactic, and you may wish to consider which side of it you'd prefer to be on.

How about this peace offering: Yes, I concede it, scientists must make assumptions. These assumptions, however, always consist of either:

1) treating something as true to precisely the extent the evidence justifies treating it as true, or

2) reaching conclusions that are explicitly dependent on the truth of the thing assumed.

I'd prefer not to be bogged down in something nobody thinks it relevant as people continue to try to pursue a senseless and meaningless 'gotcha'.

A tip for future "peace offerings"; avoid the insults.

I see you conveniently ignored the crux of my post; does the fact that everyone else disagrees with you about your interpretation mean anything to you? Does it, even at some subconscious level, suggest that perhaps, maybe, there is a slight chance of you being wrong?

 

[JoelKatz]

"To precisely the extent it's justified" is overstated, in my opinion. Since our knowledge is incomplete, we don't know such things precisely.

If our knowledge were complete, the extent it would be justified would be fully or not at all. What I mean by "extent it's justified" is the extent it's justified by our knowledge.

I would say that accepting something as true to any extent other than precisely the extent it's justified (by our knowledge, among other things) is never necessary and always error. However, making minor errors may be a reasonable trade-off, given that we can't devote infinite amount of time and precision to every choice we make.

The original statement was "All virtues are practiced in a world in which we never have complete knowledge, but must make assumptions based on what we do know and believe."

Since it clearly says the assumptions are "based on what we do know," the only thing that's baffling to me is how your reaction to the original statement was "It is never necessary to make assumptions, and it is always an error to do so."

Because in that case, how does the assumption help us? We already know the thing you are saying we need to assume. (Certainty is not a requirement for knowledge.)

Say I know from very good evidence that gravity is a 1/r^2 force. You say that to use that for further reasoning, I must assume it to be true because my knowledge that it is true is not certain. My response is, no, I don't need to assume it. And that would be a mistake because it would cause me to ignore any evidence that might suggest it's not a 1/r^2 force. Instead, I simply use it because I have strong evidence that suggests that it's true with no assuming required.

Rather than assuming it is definitely true even though I don't know it is definitely true, I simply use the fact that I know it is most likely true in further reasoning. Further, I explicitly acknowledge that any conclusions I derive are dependent on its truth. The assumption is error, because it would cause me to ignore evidence that might suggest it actually wasn't true, and I am not certain it's true.

 

[dlorde]

... even though I don't know it is definitely true, I simply use the fact that I know it is most likely true in further reasoning.

That's the assumption. You assume it's true for the purposes of further reasoning, whilst acknowledging that it may not be.

Wikipedia:
.. an assumption is a proposition that is taken for granted, as if it were true based upon presupposition without preponderance of the facts.
...
In logic, ... an assumption is a proposition that may be used to prove further propositions, in the expectation that the assumption will be discharged in due course by proving it via a separate argument.

 

[bokonon]

I simply use it because I have strong evidence that suggests that it's true with no assuming required.

Using it because you have evidence but not proof is what the rest of the world means by "assuming".

The assumption is error, because it would cause me to ignore evidence that might suggest it actually wasn't true, and I am not certain it's true.

Assuming something is true wouldn't cause me, or anyone else I know, to ignore evidence to the contrary, but I assume you know yourself better than I do.

I also assume you're someone who's incapable of admitting a mistake. If I see evidence to the contrary, I'll be sure to revise that assumption.

 

[JoelKatz]

Using it because you have evidence but not proof is what the rest of the world means by "assuming".

So this seems like a reasonable thing to say: "Once I had nearly conclusive evidence that my wife was cheating on me, I assumed that she was."

I submit no rational person would say that. They would simply proceed based on the evidence without doing any assuming. The only thing the assumption would do is prevent them from calling the original conclusion into question.

Assuming something is true wouldn't cause me, or anyone else I know, to ignore evidence to the contrary, but I assume you know yourself better than I do.

On the contrary, that's precisely what it does. That's why assuming is never justified on the base of uncertainty.

For example, we have strong evidence that suggests that marking in pen on the outside of a petri dish will not affect the growth of a culture inside. Thus, a scientific experiment can be constructed that assumes the pen marking won't affect the growth and so can use pen to mark the dishes.

However, this *will* mean that if we're wrong and the pen does affect the growth, the experiment will not detect it. In fact, it will mean such evidence might be lost, for example, because nobody's tracking the amount of pen on each dish.

However, this would be precisely the same situation even if we were 100% certain that the pen marking had no effect on the growth. It is a "formal assumption" of the experiment, and the experiment's results are conditional on the truth of it. This is so regardless of how certain we are that it is true.

That is, we would make this same 'assumption' even if we were certain of the fact 'assumed'. The assumption is not made necessary by our lack of complete information, it is simply something the experiment does not test. And we would equally well not test it if we were certain it was true.

I also assume you're someone who's incapable of admitting a mistake. If I see evidence to the contrary, I'll be sure to revise that assumption.

Point out one that I've made, and I'll cheerfully admit the mistake. In fact, I'll admit that it was a mistake for me to get myself dragged down in an irrelevant side issue that has nothing to do with the larger point.

Sure, people are always uncertain about the information they process. They are always capable of error. So what? They still have to act on the best information they have.

And "assumption" in the sense of thresholding or severing is always error. By "thresholding" or "severing" I mean we reach a point where there is sufficient evidence and then pretend we are certain and divorce the conclusion from the evidence that justified it.

 

[Mirrorglass]

Joel, you have made the claim that making assumptions leads to inability to consider the possibility that said assumptions might be false.

Leaving aside for the moment the fact that you are the only person who defines the word this way, let's go for the more pragmatic view; please provide and example where this has ever happened.

Note that a made-up story about scientists doing stupid things won't count. You'll need to show an actual case where a person blinded themselves by using the word "assume" instead of saying the same thing in an unnecessarily roundabout manner.