For believers in scientific reductionism, moral realism based on a priori knowledge or fixed “human nature” or mental access to a realm of platonic moral truths is not plausible. But I would argue that people inclined to think in terms of very long (possibly infinite) transhuman futures should be more open to a form of moral realism based on the pragmatist philosopher C.S. Peirce’s limit concept of truth, where objective truth is understood as that which a very long-lived “community of inquiry” would tend to converge on with probability 1 in the limit of infinite time to discuss and experiment (this can be elaborated in terms of the idea of societal belief systems having long-term dynamical attractors, see this paper which interprets Peirce’s concept in this way).
In the moral realm, it may be that a combination of memetic and biological evolution would tend to cause strong convergence on certain norms in the long term, perhaps because individuals can see the consequences of different norms in different subcultures and some may be more universally appealing, and/or because certain norms are more conducive to the continual growth of knowledge (David Deutsch suggested something like the latter in chapter 14 of his book The Fabric of Reality, and Peirce apparently had limited discussion of ethics but this section of the Internet Encyclopedia of Philosophy entry on Peirce’s ‘Architectronics’ says that ‘This makes ethics, for Peirce, a question of what kind of conduct is likely to see the growth of reason or rationality’). This could be compatible with both ideal observer theory (understood in terms of general limit observers rather than just an idealized version of our own idiosyncratic perspective) and the “convergent” version of coherent extrapolated volition.
For believers in scientific reductionism, moral realism based on a priori knowledge or fixed “human nature” or mental access to a realm of platonic moral truths is not plausible
Sure, but this is a case for nihilism or similar views.
In the moral realm, it may be that a combination of memetic and biological evolution would tend to cause strong convergence on certain norms in the long term
Sure, but
this doesn’t explain where the moral authority comes from, i.e. why you ought to follow the principles that could result from this process
in particular, the specific “evolutionary” formula invites an evolutionary debunking, because the theory of natural selection suggests that we converge on moral principles that tend to produce persistent societies or genes or similar, rather than ones which are morally good
a few of your points reference the “growth of knowledge” or “growth of reason or rationality” but I don’t see why (1) the described idealization procedure points toward those things or (2) why those things are good
For believers in scientific reductionism, moral realism based on a priori knowledge or fixed “human nature” or mental access to a realm of platonic moral truths is not plausible. But I would argue that people inclined to think in terms of very long (possibly infinite) transhuman futures should be more open to a form of moral realism based on the pragmatist philosopher C.S. Peirce’s limit concept of truth, where objective truth is understood as that which a very long-lived “community of inquiry” would tend to converge on with probability 1 in the limit of infinite time to discuss and experiment (this can be elaborated in terms of the idea of societal belief systems having long-term dynamical attractors, see this paper which interprets Peirce’s concept in this way).
In the moral realm, it may be that a combination of memetic and biological evolution would tend to cause strong convergence on certain norms in the long term, perhaps because individuals can see the consequences of different norms in different subcultures and some may be more universally appealing, and/or because certain norms are more conducive to the continual growth of knowledge (David Deutsch suggested something like the latter in chapter 14 of his book The Fabric of Reality, and Peirce apparently had limited discussion of ethics but this section of the Internet Encyclopedia of Philosophy entry on Peirce’s ‘Architectronics’ says that ‘This makes ethics, for Peirce, a question of what kind of conduct is likely to see the growth of reason or rationality’). This could be compatible with both ideal observer theory (understood in terms of general limit observers rather than just an idealized version of our own idiosyncratic perspective) and the “convergent” version of coherent extrapolated volition.
Sure, but this is a case for nihilism or similar views.
Sure, but
this doesn’t explain where the moral authority comes from, i.e. why you ought to follow the principles that could result from this process
in particular, the specific “evolutionary” formula invites an evolutionary debunking, because the theory of natural selection suggests that we converge on moral principles that tend to produce persistent societies or genes or similar, rather than ones which are morally good
a few of your points reference the “growth of knowledge” or “growth of reason or rationality” but I don’t see why (1) the described idealization procedure points toward those things or (2) why those things are good