Consider: “having food is good. Having more and tastier food is better. This is common sense. Transfoodism is the philosophy that we should take this common sense seriously, and have as much food as possible, as tasty as we can make it, even if doing so involves strange new technology.” But we tried that, and what happened was obesity, addiction, terrible things happening to our gut flora, etc. It is just blatantly false in general that having more of a good thing is better.
Conclusion does not follow from example.
You are making exactly the mistake which I described in detail (and again in the comments to this post). You’re conflating desirability with prudence.
It is desirable to have as much food as possible, as tasty as we can make it. It may, however, not be prudent, because the costs make it a net loss. But if we could solve the problems you list—if we could cure and prevent obesity and addiction, if we could reverse and prevent damage to our gut flora—then of course having lots of tasty food would be great! (Or would it? Would other problems crop up? Perhaps they might! And what we would want to do then, is to solve those problems—because having lots of tasty food is still desirable.)
So, in fact, your example shows nothing like what you say it shows. Your example is precisely a case where more of a good thing is better… though the costs, given current technology and scientific understanding, are too high to make it prudent to have as much of that good thing as we’d like.
As for “common sense”: in many human societies it was “common sense” to own slaves, to beat your children, again etc. Today it’s “common sense” to circumcise male babies, to eat meat, to send people who commit petty crimes to jail, etc., to pick some examples of things that might be considered morally repugnant by future human societies. Common sense is mostly moral fashion, or if you prefer it’s mostly the memes that were most virulent when you were growing up, and it’s clearly unreliable as a guide to moral behavior in general.
Now this does prove too much. Ok, so “common sense” can’t be trusted. Now what? Do we just discard everything it tells us? Reject all our moral intuitions?
Yes, by all means let’s examine our intuitions, let us interrogate the output of our common sense. This is good!
But sometimes, when we examine our intuitions and interrogate our common sense, we come up with the same answer that we got at first. We examine our intuitions, and find that actually, yeah, they’re exactly correct. We interrogate our common sense, and find that it passes muster.
And that’s fine. Answers don’t have to be complex, surprising, or unintuitive. Sometimes, the obvious answer is the right one.
Conclusion does not follow from example.
You are making exactly the mistake which I described in detail (and again in the comments to this post). You’re conflating desirability with prudence.
It is desirable to have as much food as possible, as tasty as we can make it. It may, however, not be prudent, because the costs make it a net loss. But if we could solve the problems you list—if we could cure and prevent obesity and addiction, if we could reverse and prevent damage to our gut flora—then of course having lots of tasty food would be great! (Or would it? Would other problems crop up? Perhaps they might! And what we would want to do then, is to solve those problems—because having lots of tasty food is still desirable.)
So, in fact, your example shows nothing like what you say it shows. Your example is precisely a case where more of a good thing is better… though the costs, given current technology and scientific understanding, are too high to make it prudent to have as much of that good thing as we’d like.
Now this does prove too much. Ok, so “common sense” can’t be trusted. Now what? Do we just discard everything it tells us? Reject all our moral intuitions?
Yes, by all means let’s examine our intuitions, let us interrogate the output of our common sense. This is good!
But sometimes, when we examine our intuitions and interrogate our common sense, we come up with the same answer that we got at first. We examine our intuitions, and find that actually, yeah, they’re exactly correct. We interrogate our common sense, and find that it passes muster.
And that’s fine. Answers don’t have to be complex, surprising, or unintuitive. Sometimes, the obvious answer is the right one.
That is Eliezer’s point.