Because the probability of there being a myth about Zeus, given that Zeus exists, is orders of magnitude higher than the probability of there being a myth about Zeus, given that he does not exist?
Given that the myths about Zeus attribute vast supernatural properties to him, and we now know better than to believe in any such stuff (we don’t need Zeus to explain thunder and lightning), the myths are evidence against his existence. For the ancient Greeks, of course, it was not so, but the question is being posed here and now.
Also, myths are generally told more of imaginary entities than real ones, not less. Myths are all that imaginary creatures have going for them. How many myths are there about Pope Francis? I expect there are some unfounded stories going around among the devout, but nothing on the scale of Greek mythology. So no, P(myths about Zeus|Zeus is real) is not larger, but smaller than P(myths about Zeus|Zeus is imaginary).
On the other hand, it is larger than P(myths about Zeus|no such entity has even been imagined). The latter is indistinguishable from zero—to have a myth about an entity implies that that entity has been imagined. So we can conclude from the existence of myths that Zeus has been imagined. I’m fine with that.
Also, myths are generally told more of imaginary entities than real ones, not less. Myths are all that imaginary creatures have going for them. How many myths are there about Pope Francis?
I see your problem here, you’re restricting attention to things that either exist or have had myths told about them. Thus it’s not surprising that you find that they are negatively correlated. If you condition on at least one of A or B being true, then A and B will always negatively correlate.
The original context was a slogan about myths of Zeus, but there are myths about real people. Joan of Arc, for example. So this is not true by definition, but an empirical fact.
I had no particular definition in mind, any more than I do of “Zeus” or any of the other words I have just used, but if you want one, this from Google seems to describe what we are all talking about here:
a traditional story, especially one concerning the early history of a people or explaining a natural or social phenomenon, and typically involving supernatural beings or events
Great heroes with historical existence accrete myths of supernatural events around them, while natural forces get explained by supernatural beings.
Heracles might have been a better example than Zeus. I don’t know if ancient Greek scholarship has anything to say on the matter, but it seems quite possible that the myths of Heracles could originate from a historical figure. Likewise Romulus, Jason, and all the other mortals of Graeco-Roman mythology. These have some reasonable chance of existing. Zeus does not. But by that very fact, the claim that “myths about Heracles are evidence for Heracles’ existence” is not as surprising as the one about Zeus, and so does not function as a shibboleth for members of the Cult of Bayes to identify one another.
Heracles might have been a better example than Zeus. I don’t know if ancient Greek scholarship has anything to say on the matter, but it seems quite possible that the myths of Heracles could originate from a historical figure. Likewise Romulus, Jason, and all the other mortals of Graeco-Roman mythology. These have some reasonable chance of existing. Zeus does not.
Notice that in the above argument you’re implicitly conditioning on gods not existing. We’re trying to determine how the existence of myths about Zeus affects our estimate that Zeus exists. You’re basically saying “I assign probability 0 to Zeus existing, so the myths don’t alter it”.
Given that the myths about Zeus attribute vast supernatural properties to him, and we now know better than to believe in any such stuff (we don’t need Zeus to explain thunder and lightning), the myths are evidence against his existence. For the ancient Greeks, of course, it was not so, but the question is being posed here and now.
Also, myths are generally told more of imaginary entities than real ones, not less. Myths are all that imaginary creatures have going for them. How many myths are there about Pope Francis? I expect there are some unfounded stories going around among the devout, but nothing on the scale of Greek mythology. So no, P(myths about Zeus|Zeus is real) is not larger, but smaller than P(myths about Zeus|Zeus is imaginary).
On the other hand, it is larger than P(myths about Zeus|no such entity has even been imagined). The latter is indistinguishable from zero—to have a myth about an entity implies that that entity has been imagined. So we can conclude from the existence of myths that Zeus has been imagined. I’m fine with that.
I see your problem here, you’re restricting attention to things that either exist or have had myths told about them. Thus it’s not surprising that you find that they are negatively correlated. If you condition on at least one of A or B being true, then A and B will always negatively correlate.
(BTW, this effect is known as Berkson’s paradox.)
Thanks, I knew it had a Wikipedia entry and spent nearly 10 minutes looking for it before giving up.
What definition of “myth” are you using that doesn’t turn the above into a circular argument?
The original context was a slogan about myths of Zeus, but there are myths about real people. Joan of Arc, for example. So this is not true by definition, but an empirical fact.
I had no particular definition in mind, any more than I do of “Zeus” or any of the other words I have just used, but if you want one, this from Google seems to describe what we are all talking about here:
Great heroes with historical existence accrete myths of supernatural events around them, while natural forces get explained by supernatural beings.
Heracles might have been a better example than Zeus. I don’t know if ancient Greek scholarship has anything to say on the matter, but it seems quite possible that the myths of Heracles could originate from a historical figure. Likewise Romulus, Jason, and all the other mortals of Graeco-Roman mythology. These have some reasonable chance of existing. Zeus does not. But by that very fact, the claim that “myths about Heracles are evidence for Heracles’ existence” is not as surprising as the one about Zeus, and so does not function as a shibboleth for members of the Cult of Bayes to identify one another.
Notice that in the above argument you’re implicitly conditioning on gods not existing. We’re trying to determine how the existence of myths about Zeus affects our estimate that Zeus exists. You’re basically saying “I assign probability 0 to Zeus existing, so the myths don’t alter it”.