"the light of the body is the eye"
This is incorrect. Eyes absorb light and produce electrical signals interpreted as vision by the brain. Further, it seems to me that the set of thing that 'the light of the body' describes is an empty set; there's no literal interpretation (our bodies do not shed visible light) and there's no construction similar enough that suggests an interpretation (the X of the body / the light of the X). "The light of the sun" / "The light of the moon" is the closest I can find and both of those suggest the literal interpretation.
Originally, I was going to do a very charitable reading: invent a sane meaning for "The X of the Y is the sub-Y" as "sub-Y is how Y handles/uses/interpets/understands X" and say that goals, as subparts of an agent, are how an agent understands its rationality - perhaps, how an agent measures their rationality. Which is indeed how we measure our rationality, by how often we achieve our goals, but this doesn't say anything new.
But when you say things like
You don't understand ... Maybe you'd get more out of ... You may be misinterpreting
as if you were being clear in the first place, it shows me that you don't deserve a charitable reading.
Just interpret light as ‘that which allows one to see’. That which allows the body to see is the eye.
I have become convinced that problems of this kind are the number one problem humanity has. I'm also pretty sure that most people here, no matter how much they've been reading about signaling, still fail to appreciate the magnitude of the problem.
Here are two major screw-ups and one narrowly averted screw-up that I've been guilty of. See if you can find the pattern.
It may not be immediately obvious, but all three examples have something in common. In each case, I thought I was working for a particular goal (become capable of doing useful Singularity work, advance the cause of a political party, do useful Singularity work). But as soon as I set that goal, my brain automatically and invisibly re-interpreted it as the goal of doing something that gave the impression of doing prestigious work for a cause (spending all my waking time working, being the spokesman of a political party, writing papers or doing something else few others could do). "Prestigious work" could also be translated as "work that really convinces others that you are doing something valuable for a cause".
We run on corrupted hardware: our minds are composed of many modules, and the modules that evolved to make us seem impressive and gather allies are also evolved to subvert the ones holding our conscious beliefs. Even when we believe that we are working on something that may ultimately determine the fate of humanity, our signaling modules may hijack our goals so as to optimize for persuading outsiders that we are working on the goal, instead of optimizing for achieving the goal!
You can see this all the time, everywhere:
There's an additional caveat to be aware of: it is actually possible to fall prey to this problem while purposefully attempting to avoid it. You might realize that you have a tendency to only want to do particularly prestigeful work for a cause... so you decide to only do the least prestigeful work available, in order to prove that you are the kind of person who doesn't care about the prestige of the task! You are still optimizing your actions on the basis of expected prestige and being able to tell yourself and outsiders an impressive story, not on the basis of your marginal impact.