Sam Harris has recently given a talk at TED entitled “Science Can Answer Moral Questions“. This talk has garnered a lot of attention, and has been fairly controversial, as Sam Harris’s opinions tend to be in general. Sean Carroll has weighed in over at Cosmic Variance. I posted a lengthy comment there detailing my thoughts, which I repost below.
Hi Sean, interesting comments here, but I mostly disagree with you. By the way, Sam is soliciting criticism of his talk over at http://www.samharris.org/ted_talk, so I’d suggest you link him to this post.
Now, to the disagreement. It’s true that one will never be able to derive moral principles without making some assumptions, like axioms, at the base of everything. You are aware of this, stating “But what if I believe that the highest moral good is to be found in the autonomy of the individual, while you believe that the highest good is to maximize the utility of some societal group?” Clearly if you begin with different goals you will reach different conclusions about what are the most moral actions. And of course those conclusions should be informed by the facts of the matter – for example, there may be ways to enhance “the autonomy of the individual”, and if you’re wrong about what those ways are, then you will fail in your goal.
But science is no different! Of course the Big Bang is based on facts, but it’s also an inductive generalization, and nothing in the facts tells us that any particular prediction of Big Bang theory is guaranteed to be right. At the base of science there are assumptions, for example, assumptions about how much confidence we should place in inductive generalisations. It’s mostly just an intuition, but that’s enough to get started, and we can make great progress once we stop worrying about the fact that our foundations are not absolutely set in stone. The foundations are solid enough to make progress, and we should not obsess too much over them. Your reaction to Sam’s talk seems to me to be equivalent to a radical sceptic thinking you’re wrong about the Big Bang because it’s impossible to have perfect knowledge.
In ethics, I think the situation is much the same. Once you decide on a goal (for example, wanting conscious beings to be in more pleasant brain-states), the methods you should use for deciding what actions are moral are basically the methods of science. I see this as Sam Harris’s main important point, but there is another. Now, of course you could choose a different goal and then you would get different conclusions about what constitutes acting ethically. Here, I think Sam makes a second major point (that I also agree with): that wanting conscious beings to be in more pleasant brain-states is implicitly the goal of the vast majority of moral systems. Even religious ones: for example, a fundamentalist Christian who believes in a literal hell may be justified in quite radical acts here on Earth – and this would be right if it was expected to prevent future eternal suffering of conscious beings. The error here is scientific: the evidence for a literal hell is so weak that there almost certainly isn’t one. Also, people who advocate individual freedom, or strong communities, do so because they think it produces the best lives for people – not because it’s an end in itself.
The foundations of ethics, and science, are not absolutely rock solid – but that’s okay. They’re solid enough to make progress. There is a place for intellectual hand-wringing about foundations, but that doesn’t mean that anything goes and that we may as well give up.
session, I hit a sweet spot in coding productivity and wrote a bunch of scripts to extract spatial features from galaxy images, along lines suggested to me a week or so ago by Andrew Zirm. These features are extracted from a matrix that encodes the frequency of adjacency between threshold intensity levels in the image. It’s the sort of thing best shown with pictures, which perhaps I can post once Andrew has decided which direction to pursue next.
So, here is what happened today: I had a wisdom tooth taken out. It was impacted, which means that it was at an angle of somewhat less than the usual pi/2 radians relative to the gum-line and so obstructing access to its root, as though it knew it would one day be the target of this sort of operation. To get through the tooth itself, they used a technique that is new to me, called 
Letters to Nature 