eli5: Carl Sagan’s absence of evidence

5.42K views

Big fan of Carl Sagan, he was like a father figure to me, I’m partially molded by him.
That said, something he used to say all the time really baffled me, still does:
“Absence of evidence is not evidence of absence”
He said this when talking about aliens.
However: Sagan was a famous non believer.
How does this aphorism reconcile with the existence or non existence of a god?
If “absence of evidence is not evidence of absence” does that apply to a god as well?
Is there a god even though there is no evidence of him/her/it?

In: 95

147 Answers

Anonymous 0 Comments

To some degree, this comes down to prior probabilities and direct and indirect evidence. So, there’s an absence of direct evidence of aliens, but we know that we exist, and there are many stars, with new exoplanets being discovered practically daily, so the indirect evidence of at least the preconditions for life is pretty high. When it comes to gods, there seems to be a lack of direct evidence, and the indirect evidence doesn’t seem, well, evident. So, the phrase “absence of evidence isn’t evidence of absence”, when placed in a larger context, makes more sense, to me at least.

Anonymous 0 Comments

I like to pair that expression with another Saganism: “extraordinary claims require extraordinary evidence.”

Just because there’s no evidence for something, it doesn’t mean that thing definitely doesn’t exist. On the other hand, if you’re going to make an extraordinary claim, you better have some pretty compelling evidence to back it up.

If your claim is that it’s statistically likely that intelligent life on other planets exists, but that it’s so far away we’ll likely never encounter it, that’s not a particularly extraordinary claim. There are 200 billion trillion stars in the universe, and a truly unfathomable number of planets. The idea that on at least one other planet somewhere out there, there is sentient life, is not a particularly extraordinary claim, so even though we don’t have any direct evidence, it makes sense to believe it’s likely.

On the other hand, the claim that there is an omniscient, omnipotent being who controls the universe and all of our lives and creates the cold and everything in it, and so on, that’s … pretty extraordinary. If you want me to believe that’s likely, you’re going to need to show me some evidence.

If you tell me your neighbour owns a golden retriever, I may not have any evidence that dog exists, but it seems fairly likely to be true, and even if I don’t have any proof, it’s reasonable to believe you.

If you tell me your neighbour owns a six-legged dog-moose hybrid with purple polka dots and wings, I’m gonna want to see some proof before I accept it as true.

Anonymous 0 Comments

Can god exist if two people (societies) have a deep belief in omnipotent yet conflicting evidence of god?

Anonymous 0 Comments

Can god exist if two people (societies) have a deep belief in omnipotent yet conflicting evidence of god?

Anonymous 0 Comments

Can god exist if two people (societies) have a deep belief in omnipotent yet conflicting evidence of god?

Anonymous 0 Comments

An even simpler way to explain this principle, I think, is explaining “Onus Probandi” or “burden of truth” – this holds that any assertion is an argument for the truth of that assertion, and all assertions require proof. The “Onus probandi” or “Burden of Proof” is on the person making the assertion. This is considered true for *all* assertions in philosophical discourse.

So: “There are definitely aliens” requires a proof, but so does “There are definitely no aliens” just as “There is a deity” requires a proof, but so does: “There is definitely no deity”

As it stands, these two assertions are equally difficult to provide proof for, since “I cant find a way to measure a thing” isn’t any proof that the thing isn’t present.

Anonymous 0 Comments

An even simpler way to explain this principle, I think, is explaining “Onus Probandi” or “burden of truth” – this holds that any assertion is an argument for the truth of that assertion, and all assertions require proof. The “Onus probandi” or “Burden of Proof” is on the person making the assertion. This is considered true for *all* assertions in philosophical discourse.

So: “There are definitely aliens” requires a proof, but so does “There are definitely no aliens” just as “There is a deity” requires a proof, but so does: “There is definitely no deity”

As it stands, these two assertions are equally difficult to provide proof for, since “I cant find a way to measure a thing” isn’t any proof that the thing isn’t present.

Anonymous 0 Comments

I want to mention the teapot but I can’t remember who’s it is. Somebody add it so OP can google/wiki.

Anonymous 0 Comments

I want to mention the teapot but I can’t remember who’s it is. Somebody add it so OP can google/wiki.

Anonymous 0 Comments

It does, and that is where belief comes in. Nobody can prove that God exists, nor can they prove God does not exist. This leaves everyone with their beliefs, people either believe they do, believe they don’t, or the often misunderstood third stance of don’t know, can’t know so don’t spend time thinking or worrying about it.

“Believers” feel (right or wrong) they have experienced things and seen things that support that a God exists. “Non-Believers” feel (right or wrong) they have not seen or experienced things that support the idea of a Deity.