Dhorpatan's logic of absence IS absence of logic.

[BrooklynRagtag]

Other than an absence of confirming evidence, what evidence could you possibly cite in favor of the non-existence of a thing? How would you demonstrate it?

[jonThedrummerify]

Interesting video. However, I think the dollar bill in the drawer argument is not analogous to the argument that an immaterial/eternal/omnipotent/­omnipresent being or deity does or doesn't exist, because it is not against the laws of space, time, and matter for a dollar bill to be in that drawer. An eternal, all knowing, and immaterial being is, however, in direct violation of the laws of our universe. That is a very important thing to take into account.

[adavidpirtle]

There is evidence that the dollar bill is not in your hand.

[Birdieupon]

Thank you for making this video. It is an excellent explanation of the AoE=EoA fallacy which Dhorpatan appeals to. As you say, if you do not have evidence for a claim, it may just be that you don't have *access* to the evidence, and thus you would have the same observation whether or not X is true or false.

Whereas if you can say:

1. If X then we should expect to be able to see Y.

2. We are able to, yet do not see Y.

3. Therefore no X.

Such an argument, indeed, *becomes* evidence in itself.

[iamgoddard]

@Birdieupon, nice application of Peircean abduction!

But IAmTheScum13 is saying AoE=EoA is true sometimes. He says the video of his empty hand is an absence of evidence of a dollar in his hand, and so absence of evidence can yield evidence.

To the contrary, I say the example shows that we're only getting evidence from the *presence of evidence* seen that contradicts the 'dollar in hand' claim. So as a universal rule, 'absence of evidence' never generates evidence.

[iamgoddard]

Video of an empty hand is the *presence* of a negating observation wrt the 'dollar-in-hand' claim. But the presence of a negating observation is NOT an example of absence of evidence. So again, 'AoE=EoA' is always fallacious.

[Birdieupon]

@iamgoddard

I agree. Overall he makes the right point, but indeed it is better to say it's not the absence of evidence, but the absence of the dollar bill lol! If someone can construct a sound modus tollens argument, then it's true to say that there is a presence of evidence to contradict the claim "I have a dollar bill in my hand" (or to support the claim "I don't have a dollar bill in my hand").

So yes, as you say AoE is *never* EoA because the argument *itself* is evidence.

[iamgoddard]

A fast logical analysis concurs with your conclusion:

If absence of evidence is evidence of absence,

then: no evidence = evidence.

But that's a contradiction of identity, -A =/= A.

Therefore, absence of evidence is NOT evidence of absence (or of anything).

[IAmTheScum13]

@iamgoddard That's not quite right, because in this case, "evidence" is referencing two different things.

For example: If my right hand is not dominant, then my left hand is dominant. This isn't actually true, but let's roll with it. "Dominance" references two different hands, as "evidence" before is referencing two different propositions.

[iamgoddard]

@IAmTheScum13, 'Dominant hand' means the same thing whether it references you left or right hand.

Perhaps you can explain directly, not by analogy, how 'evidence' in "absence of evidence" and "evidence of absence" have different meanings.

[iamgoddard]

IAmTheScum13 wrote: "as "evidence" before is referencing two different propositions."

Since I don't see your point, perhaps I should note that the word 'evidence' does not reference propositions. The word 'proposition' references propositions.

[iamgoddard]

Agree with your conclusion, but differ on this:

That "there is no evidence for the dollar" in your hand (as you say) does not adequately model the given state of affairs. A better modeling is: There IS visual evidence for the nonexistence of a dollar in your hand.

So the example is not an example of 'absence of evidence', and hence Sagan's axiom, "An absence of evidence is NOT evidence of absence," is not shown to be false sometimes (and you seem to say it is false sometimes).

[IAmTheScum13]

@iamgoddard But then I would ask, what is the evidence for the nonexistence of the dollar, and you would cite your lack of visual perception of the dollar. Visual perception of the dollar would count as evidence for the existence of the dollar, therefore you lack evidence.

[iamgoddard]

@IAmTheScum13, the evidence for the lack of the dollar in your hand is the presence of contradictory evidence, not the absence of evidence.

[Jayoung1000]

Good video

[Darkconis]

@IAmthescum13 Your reasoning is pretty good. But I must say, if x could be true, but we don't know where to look for evidence, or we cannot look where we think there maybe evidence. Then x is then a mute point of speculation. And logic cannot be, in itself, a transcendent truth.But even if somebody wants to use logic as a transcendent tool for truth, the existence of a single deity gets lost in the infinite of unknowns. But good vid.

[Gunriffun9mm]

Are the two of you arguing the existence of god? If so, who is the atheist and who is the theist? Perhaps this is just a logical-philosophical debate.

I shall rewatch this after I've slept some. This video has caught ahold of my interest. Good day.

[Dhorpatan]

Here's how the Absence of evidence works. if you make a CLAIM that there is a dollar bill in your desk drawer; but you never present any valid objective evidence to back up that claim, that absence of evidence for your claim, is evidence that your claim is absent of truth. And this is reasonable until otherwise refuted. Its evidence your claim is false, IT DOES NOT PROVE IT.

[IAmTheScum13]

@Dhorpatan And that leaves us with an interesting dichotomy. We have two claims.

There is a dollar bill in my in my desk drawer.

There is no dollar bill in my desk drawer.

Both lack evidence. So by your standard, it's reasonable to believe their negations (which result in the same two initial claims) simultaneously. You are falling into the absurd reasoning I highlighted in the second half of the vid.

[Dhorpatan]

@IAmTheScum13

You're simply ignoring refutation. I just made a prior comment that said Absence of evidence is not divorced from logic, reason, and context. This is so obvious, that it goes without saying, which is why I didn't. It's contextual, like so much of reason and logic. There is a dollar bill in your desk drawer? OK, and if no evidence for that claim is given(when evidence should be expected or is asked for), then that is evidence that your claim has an absence of truth.

[Birdieupon]

@Dhorpatan

"if no evidence for that claim is given(when evidence should be expected or is asked for), then that is evidence that your claim has an absence of truth."

Dude, what if the claim was "I do NOT have a dollar bill in my drawer"? By your logic, the AoE would make it more likely that he doesn't have it either! You talk about evidence being expected, but that's the point: you're asking for evidence to find the truth, not relying upon the absence of it. You've given no valid refutation.

[Birdieupon]

@Dhorpatan

Sorry dude but your logic is completely invalid. Allow me to explain also:

There are only 2 possibilities:

a) the $ bill is in the drawer

B) the $ bill is not in the drawer

In EITHER case, your observation is the same:

proposition "a": absence of ev.

proposition "b": absence of ev.

You cannot use appeal to ignorance in judging the negation of either claim to be more likely. You need *evidence* to tip the scales of likelihood. You have failed basic logic with your argument here.

[Birdieupon]

@Dhorpatan

"Its evidence your claim is false, IT DOES NOT PROVE IT."

Using caps won't make your point any more valid. What would you say in response to the claim "the coin I tossed landed heads" but you couldn't see the coin? Would you conclude that the AoE made it more likely that it was tails? It's clearly absurd.

You're right: it doesn't prove it, but neither does it tell us *anything* about the likelihood of its truth value. You'd need a modus tollens argument when dealing with absence.

[Pelonetillo]

"more likely" relative to what? given the context youve provided in your comment, there is more than one answer to that question. youre focused on one; thats why youre confused.

[Birdieupon]

@Pelonetillo

""more likely" relative to what?"

I'm merely quoting the words of Dhorpatan himself, who said absence of evidence for a claim makes its negation "more likely" and pointing out this is fallacious.

[Pelonetillo]

you didnt get it.

the likelihood in question is that of the claim being true; but youre focused on the likelihood of the coin landing a certain way--wrong focus.

[Birdieupon]

@Pelonetillo

"the likelihood in question is that of the claim being true; but youre focused on the likelihood of the coin landing a certain way"

What the hell are you talking about? According to Dhorpatan, AoE for a claim makes its negation MORE LIKELY to be true. This would mean if I said "it's heads" then his faulty logic would imply I should be more inclined to believe that the coin landed tails (i.e. that "heads" is not true). It's not even clear what your objection is? Maybe its just BS.

[Dhorpatan]

But absence can't be used as evidence unless it meets a given standard of reason and logic. This is so obvious, it almost goes without saying, which is why it's generally not. Where in my argument did I ever say absence of evidence is not contextual? It's so obvious, it should go without saying, since that's the very basis of evidence. Something that is EVIDENT, apparent, logical, reasonable.

[Dhorpatan]

Your argument fails too when you used the "for the sake of argument". it's obvious that the absence of evidence comes into play in your example only if we look in the drawer, and expect to find evidence of the dollar bill, and find none. Saying there is not a dollar bill in your desk drawer is not EVIDENCE if I didn't even look there. Absence of evidence is evidence of absence, but I didn't say it was divorced from reason and logic.

[IAmTheScum13]

@Dhorpatan Let me ask you this: Do you lack evidence of a dollar bill in my drawer, or do you not? Any attempt at saying, "Well, if I looked..." is irrelevant. Do you, or do you not? Obviously, you do lack this evidence.

Therefore, by your logic, you MUST conclude that there is no dollar bill in there.

[Dhorpatan]

Did you have to put the slightly insulting title. And what you say between 1:13-1:22 shows there was no absence of logic on my part. if there was, you would have been far more negating then "sometimes we can".

[IAmTheScum13]

@Dhorpatan You should probably watch the rest of the video. I show why your argument does not conclude truth, and replace it with an argument that does.