Forgive me, but I'm still not sure I understand. Not least because the last of my propositions seems awfully like what a utilitarian would say about utility, but you say (1) none of my propositions matches fitnessist claims and (2) fitnessism is a moral theory just like utilitarianism.
If I want to know whether someone's a utilitarian, I ask questions like:
So, if "fitnessism" is the same kind of thing and you are a fitnessist, should I conclude that you ...
For example:
(Suppose, in each case, that I have no living relations close enough and in enough need of my help that I can do much for my inclusive fitness by focusing on them rather than on my own progeny.)
Would you, in those situations, be likely to act in the manner that maximizes your genetic fitness?
Perhaps I'm wrong in saying that a fitnessist should be expected to approve of other people's fitness-maximizing actions, and to advocate fitness-maximization in others. After all, while a utilitarian is (allegedly, at least) trying to maximize a kinda-objective quantity that's meant to be the same whoever is doing the maximizing, fitnessism (AIUI) explicitly says that your fitness is not my fitness and each of us is (should be?) maximizing our own. And often (usually?) your fitness and mine will conflict more than they concur.
But if so, then I find it hard to see fitnessism as an ethical theory. (I have the same problem with, e.g., hedonist egoism.) If being a fitnessist just means aiming to increase one's own genetic fitness, isn't it just a preference like liking to eat chocolate?
In what ways does fitnessism go beyond the following statement: "People (and other animals) have a tendency to act in ways that in evolutionary history have resulted in more copies of the genes they carry."?
No worries! I appreciate that you ask questions. First I will make some clarifications about the four points in your previous comment.
The proposition: "People and/or other animals actually act so as to maximize genetic fitness" is, as you stated, not true. There is no disagreement about this.
We do not "get from there to" ethical fitnessism. In fact, we do not violate Hume's law at all, i.e., we do not deduce any normative ethical statement from a set of only factual statements.
The statement that: "'Acting so as to maximize g
I noticed that there has been some earlier discussion about Sam Harris’s Moral Landscape Challenge here at LW. As a writer on the Swedish politico-philosophical blog The Inverted Fable of Reality, I would like to share a response to the challenge, written by our main contributor, which I believe is interesting to read even if you are not familiar with The Moral Landscape or its content. See this link for the response and a short explanation of the challenge.
The response takes a different approach to most responses to the challenge. It is divided into four parts and starts by asking which ethic is most compatible with science and reality and finally tries to answer this question.