Do we value keeping fish alive more than keeping old people alive via power-hungry air conditioning?

There are millions of similar conundrums, none of which are solvable via appeal to objective truths.

Put another way, you can only have a logical argument with someone who already agrees with your beliefs.

Technically true, but that's an easy (and all too frequently used) way to dismiss other people's arguments and keep believing whatever you want.

It's very unlikely that any real-world policy question is a question about your fundamental value. You most likely don't value marijuana intrinsically. The future of a river dam is probably not the real center of your morality. Rational reasoning is useful to illuminate connection between the subject of an argument and your moral values. A connection that usually is pretty complex, and allows for honest and patient enough people to reach the same conclusion given the same knowledge about the problem.

Consider the towns and cities by bodies of water that have either dried up or been polluted. It's financially ruinous because it either/or kills tourism and/or fishing industry; the salty dust left behind by water causes horrible health problems; there's natural brain/brawn drain that leaves only the older and sickly behind to either fend for themselves or be on gov pay check. Just off the top of my head. I can easily think up a lot more effed up scenarios that have already happened in the world (see Aral Sea).

But along the way to the unfortunate end you describe above, many good things came of the dam. Any calculus needs to evaluate the tradeoffs. "Were they worth it?" doesn't lend itself to objective-factual analysis, because "worth" is all about values.

Those tradeoffs are "hard to decide via objective truths" only because they haven't been decomposed enough. You have to dig deeper into them, split them apart, ask why do we care about something, and then ask again and again. It might get hard to keep track of the expanding tradeoff space, which is probably why people shy away from digging into things too deep. But if you do the work, you may find out that there is a way to solve the original problem in a way that satisfies everyone's low-level values.

Reminds me of essays of Bret Victor, who occasionally seems to be making a related point - a lot of policy debates quickly devolve into appeals to emotions, because we lack tools to effortlessly decompose and analyze actual problems. See e.g. http://worrydream.com/ClimateChange/#media for a good example.

So are engineering problems.

No, it's not the only way. It's the easy way.

The hard way is to consider other consequences of both choices, including long-term effects, including changes that aren't 0%-100%, but slightly change probability of other events.

Hurting the ecosystem might increase the probability of flooding the area, which will hurt some of the people that you are trying to comfort by giving them cheaper energy. So, maybe it's objectively irrational to build the dam, no matter whether you value people or fish more?

Maybe the population in the area is decreasing anyway and cheap power won't help? We can predict such things pretty reliably. So why build a huge dam and hurt environment if in 40 years it will be useless?

It's impossible to know for sure, but it's possible to estimate. Abandoning the rationality altogether just because it's not immediately obvious what to do is very irresponsible.

I know it was just an example, but IMHO it's a representative example. Many of the issues in the center of the public debate now are objectively scientifically solved, or so close to be solved, that it doesn't matter what the exact details are.

Yet people continue to argue about them because of tribal thinking, religion, corporate interests, etc. See global warming, equality for sexual orientations, war on drugs, public vs private healthcare, etc.

OC proposed that human element is inherently unpredictable, so rationality isn't the solution. Yet - thanks to the law of big numbers - big groups of people are more predictable than small groups of people or individual people. So we may not know who will vote X or Y, but we can predict how many people will vote X and Y with reasonably small error. We have big data, that can predict you're pregnant before you know you're pregnant, just basing on you browser history FFS.

Seriously, a better way would be to start doing 5-whys on this, instead of going for "non-objective things". A quick attempt will tell you that we care for both ecosystem and power, but depending on the local context, we might care more about one or the other. Maybe we can import power from elsewhere, or put a dam in a place where it won't disturb ecosystem so much. Maybe the ecosystem can handle the dam, or really the power is desperately needed.

You can quantify this all if you bother. Problem is, most people don't bother, they very quickly stop thinking about it, and start going by their gut.

(I'd say, they stop behaving like adults, but since a lot of adults have this problem, I guess we need a different phrase.)

Caring more about one or the other is exactly the issue. The reasoning about the degree of which to care about either at all is the issue that cannot be resolved objectively.

Putting a dam in place that won't impact the ecosystem so much--sure, we can minimize the tradeoffs, but the tradeoffs remain, and all resolve to what we value vis a vis what it costs. Which is not objective.

Think of it as akin to mathematics. Mathematics starts with axioms, which can be completely arbitrary, and then derives an entire universe from them by following only objective, formal reasoning. Similarly here, you have some personal values that are (to some extent) arbitrary, but accepting those, you get to use objective reasoning to devise a set of tradeoffs that satisfies those values the best.

Also sometimes different people with different values aren't really in conflict, they just don't have enough knowledge to realize their values aren't being violated. Fix that, and you can get agreement.

Why are those non-objective?

There is no objective answer to that question.

Prove it.

Wrong.

Both the fish and the electricity need to be considered in a long term utilitarian framework.

The only reason you seem to have two conflicting objective truths is because your time window is too short.

Says who?

You have an infinite regress problem here. You eventually are going to have to fall back on non objective feelings about how the world should be to justify your actions.

Depending on how you define "utility" - this is either a meaningless tautology that doesn't say anything at all, or a subjective belief that can be easily challenged by equally subjective alternatives.

Evidenceless beliefs are what need to dictate the goals of policy, because there is no other way to decide on a goal. Once the goal has been decided, objective truths must be what determine the best way to reach that goal.

I disagree: I am strongly opposed to force by violence (laws) to prevent people from doing stupid things to themselves. In this sense, I do not necessarily consider saving lives a good thing (of course, there do exist lots of cases where I do).

P.S.: I strongly recommend wearing seatbelts, but am opposed to seatbelt laws.

From what I've been told and have read, the fines for not wearing a seatbelt are less about preventing people from making a potentially life threatening decision and more about preventing people from making a really bloody mess that tax payers then have to pay to clean up. A dead body strapped inside of a car is a lot easier to clean up than a dead body thrown 60 feet down the road and torn into who knows how many pieces in the process. Not to mention that what is the equivalent to a human cannonball can cause further damage to property and people who are unfortunate enough to be in the way.

Thinking of the fine as "Increasing Cost to Society" instead of "Preventing you from endangering yourself" makes it more agreeable to me - as I think we agree on the stance that laws that prevent people from doing stupid things to themselves aren't good laws. Laws that reduce wasteful costs to society so that funding can be put into less wasteful things, in my opinion at least, are good laws though.

Since most laws against preventing people from doing stupid things to themselves saves wasteful spending - I agree with them within that framing of the picture.

You are forcing folks to internalize an externality. Same with carbon cap & trade schemes. Same with helmet laws. Same with toll roads. Etc...

We already do this in a quite literal way with money, the price of things follows the subjective valuation of those things, so for example if a bit of paint on canvas in a frame which would otherwise only be worth $40 is the Mona Lisa, then it is suddenly (and seemingly magically) worth $800 million. You could use this to evaluate joy and harm as well, in the form "what is the maximum amount of money you would spend to be able to eliminate this harm or to experience this joy?"

Is it? Any kind of value system must presuppose the value of life because only life can hold something valuable. Value systems that do not are therefore inconsistent.

It would be a rather silly value system for a human to have, but there wouldn't be any inconsistency in it.

With the invention of machines we could replace life with more efficient automated systems that produce paper clips, but stupid machines cannot adapt to changing circumstances, like outside threats in the form of asteroids, climate change, earth quakes, and so on. Therefore the machines should be at least as intelligent as possible so as to adapt to any circumstances and ensure the continued production of paper clips.

Intelligent machines are simply another form of life. This obviously wouldn't happen overnight, but with the gradual introduction of more and more technology, the creators would more and more integrate with their machines.

Any value system that denies the value of life is simply inconsistent.