True: we disagree, and at least one of us is wrong.
This doesn’t follow. Compare it to the rules of an artificial game. It can be true that at time (t_1) the team was offsides, even if at time (t_2) the game is over and the teams have disbanded and a fair has been set up on the playing field rendering the concept of ‘offsides’ meaningless.
So too can we identify moral rules that apply now, that are rational and necessary now, and that will remain rational and necessary now ((t_1)).
Moreover, an enduring future is not sufficient for morality. Nothing about an infinity of time entails morality.
Thanks for this response, you make some points that hit directly at the original premise.
First, I do think morality is objective even if it’s contingent. As I’ve argued elsewhere, morality has an identifiable goal (make the group survive); it is present in all normal humans as an instinct (though it isn’t present in certain mentally handicapped people like psychopaths); and its specifics are learned. I think that accounts for its change overtime, and the need to teach much of it (but not all of it) to children.
Second, regardless of money’s role in a specific society, money is also an abstract concept, and I’d argue that it can be applied to any society in which trade occurs (and possibly to others). As I’ve stated repeatedly, without justification or clarification, money mediates value. By that I mean that money is an external representation of value, and that anything one values, in whatever way they value it, can in theory be represented in monetary terms. This is clearly true for anything of value that people actually do buy and sell for money. But I would take it further. We (thankfully) no longer buy and sell people (at least openly, in the first world), but we can’t get away from the need to estimate the monetary value of a human life so long as things we do buy and sell interact with human lives.
This doesn’t have to be sinister. When we’re building a car, we can keep adding safety feature indefinitely. We’ve literally build vehicles that can protect someone in a fall from space, we could make cars significantly safer than they are. The trade off is price. If I tell you that you can modify a car in a way that will reduce the odds that you’ll die in it by .001% and it will cost you $10,000 to add that feature, you can either accept that exchange or not. And when you make that choice, you implicitly provide information about the price your life. If the probability of a reduction in death doesn’t seem worth it, you are saying that the risk-weighted value of that increased safety is worth less than $10k, and we can work backwards from there to calculate an upper limit on the subjective monetary value of your life.
We can do something similar to compare across cultures, by taking aspects of human biology that are constant. Take something like “minimum nutrients necessary to fuel a human through their natural lifespan.” That value is roughly constant across time and place. We can look at what that costs in modern society, that use that as a baseline to price other goods in places where money isn’t used. If we know that food is traded for protection in some place and time, and we know that food bears a certain relationship to the minimum nutrients necessary to fuel a human through their natural lifespan, we can calculate how valuable protection is in that time and place. All we need is a series of relative measures, and as long as we can relate them back to something that preserves its meaning into our time and place, we can express the values in those others places and times, regardless of the role money played in those societies.
Finally, we can use these tricks to evaluate things that people aren’t willing to sell for money. Something like honor or love, which by their nature can’t be purchased in practice, can still be priced in theory, because in the course of human affairs we necessarily make tradeoffs between these values that reveal our preferences in a way that can be expressed in prices. And so, for example, the value of marriage is estimated to be about $100k/year: