"Does this sound like what you mean by a "beneficial irrationality"?"

No. That's not really what I meant at all. Take nationalism or religion, for example. I think both are based on some false beliefs. However, a belief in one or the other may make a person more willing to sacrifice his well-being for the good of his tribe. This may improve the average chances of survival and reproduction of an individual in the tribe. So members of irrational groups out-compete the rational ones.

In the post above Eliezer is basically lamenting that when people behave rationally, they refuse to act against their self-interest, and damn it, it's hurting the rational tribe. That's informative, and sort of my point.

There is some evidence that we have brain structures specialized for religious experience. One would think that these structures could only have evolved if they offered some reproductive benefit to animals becoming self-aware in the land of tooth and claw.

In the harsh world that prevailed up until just the last few centuries, religion provided people comfort. Happy people are less susceptible to disease, more ambitious, and generally more successful. Atheism has always been as true as it is today. However, I wouldn't recommend it to a 13th century peasant.

"I propose that what seems truly beneficial, seems both true and beneficial, and what seems beneficial to the highest degree, seems right."

This is not true a priori. That is my point. My challenge to you, Eliezer, and the other denizens of this site is simply: "prove it".

And I offer this challenge especially to Eliezer. Eliezer, I am calling you out. Justify your optimism in the prudence of truth.

Disprove the parable of Eve and the fruit of the tree of knowledge.